1. Chemistry

    You find a compound composed only of element x and hydrogen,and know that it is 91.33% element x by mass. Each molecule has 2.67 times as many H atoms as x atoms. What is element x ?

    asked by Andrew22 on April 22, 2010
  2. Chem

    True or false: In chemistry, the mole is used the same way that a grocer would use a dozen. It is a number representing a quantity that is independent of mass or volume. True False False Avogadro’s number: A Equals 6.02 × 10^23 molecules/mole. B Is used

    asked by Anonymous on June 15, 2020
  3. biology

    Choose the total number of each item requested below. 4C6H12O6 Carbon atoms Hydrogen atoms Oxygen atoms Molecules

    asked by Anonymous on October 29, 2012
  4. chemistry

    Question 1. A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing This Equation? Choose

    asked by Jen on September 23, 2008
  5. chemistry

    are these right? How many atoms are there in 1.3x10^22 molecules NO2? atoms=(1.3x10^22 molecules NO2) x (2atoms/1molecule) = 2.6x10^22 atoms NO2 A 5.0g sample of O2 is in a container at STP. How many atoms of oxygen are in the container? atoms = (5.0g O2)

    asked by s on December 14, 2008
  6. Chemistry

    Write the chemical formulas for the compounds containing each of the following: a) one calcium atom for every two iodide atoms. b) two nitrogen atoms for every four oxygen atoms. c) one silicon atom for every two oxygen atoms. d) one zinc atom for every

    asked by Melissa on July 1, 2010
  7. Chemistry

    A compound containg 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide (CO2) and water. What element should you look at first in balancing this equation? Is

    asked by Mickey on July 4, 2008
  8. Chemistry

    Which of the following are key parts of Dalton's Atomic Theory (Click the 4 that apply)? (1 point) All elements are composed of tiny indivisible particles called atoms*** Atoms of the same element are identical. The atoms of any one element are different

    asked by Spring Allergies on September 30, 2019
  9. Biology

    |Question| Living organisms are composed of millions of organic compounds, each having a unique structure. What element is responsible for this huge diversity of molecules? Describe the diversity of structures that can be formed and the properties of this

    asked by jack the cookie monster on August 30, 2017
  10. chemistry

    Examine the scenario. A magnesium (Mg) atom gives one electron to two atoms of another element, and takes on a 2+ charge. The two atoms of the other element each form a 1− charge. As a result, the magnesium ion and the two ions of the other element

    asked by please help on August 30, 2017
  11. gen.science

    A compound containing 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide and water. Which chemical or element will have the largest number of moecules?

    asked by charlie on June 21, 2010
  12. Earth Science (check answers)

    1. The mass number of an atom is obtained by totaling the number of_____and____. a. electrons and protons b. electron and neutrons c.protons and neutrons d.neutrons and isotopes Is it B? 2. Which of the following statements about the chemical combinations

    asked by Ember Lovet on August 8, 2017
  13. Chemistry

    A compound containg 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide (CO2) and water. What element should you look at first in balancing this equation? Is

    asked by MV on July 4, 2008
  14. chemistry

    a carbon containing 3 atoms of carbon and 8 atoms of hydrdren combinend in reactionwith oxygen molecules the 2 end products of this equation are carbon dioxide co 2 an water what element should i look at first inn this oxygen hydrogen carbon or dioxide and

    asked by andrea on May 12, 2008
  15. Chemistry

    Question 1. A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing This Equation? Choose

    asked by Jen on September 23, 2008
  16. Chemistry

    Question 1. A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing This Equation? Choose

    asked by Mickeyv on July 8, 2008
  17. Chemistry

    Question 1. (SEE QUESTION 2 ) A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing

    asked by Mickeyv on July 8, 2008
  18. chemistry

    Equal masses of gaseous N2 and Ar are placed in separate flasks of equal volume at the same temperature. Tell whether each of the following statements is true or false. Briefly explain your answer in each case. (a) There are more molecules of N2 present

    asked by Gabriela on March 30, 2007
  19. general science

    A Compound Containing 3 Atoms Of Carbon And 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The Two End Products Of This Equation Are Carbon Dioxide And Water. What Element Should You Look At First In Balancing This Equation?

    asked by jennifer on August 9, 2009
  20. chemistry

    a compound containing 3 atoms of carbon and 8 atoms ofhydrgen is combined in a reaction with oxegyn molecules the two end products of this equation are carbon dioxide co 2 and water what elemement should i look at first in balancing this equation oxygen

    asked by andrea on May 12, 2008
  21. Chemistry please check

    1. Which of the following would occur as saturated hydrocarbons? alkanes alkenes alkynes cycloalkynes ans: alkanes 2. There are millions of organic compounds but only thousands of inorganic compounds because atoms of elements other than carbon never

    asked by Mary on February 25, 2008
  22. CHEMISTRY

    An element X with electronic configuration 2,8,2 ionises to a configuration of 2,8 when it combines with another element Y of configuration 2,8,7? (i) state the type of bonding formed between the two elements. (ii) write a simple ionic equation to

    asked by NUT on June 8, 2019
  23. science

    What is the difference between liquid water and water vapor? A: They are different states of the same pure substance B: They are different types of chemical compounds. C: They differ in there number and types of atoms D: They have different arrangements of

    asked by rose on November 30, 2018
  24. physical science

    I have been working on my homework for science for a while now and I just wanted to see if I got any questions wrong. Can someone help me by checking what problems i got wrong. My parent told me that I have at least 5 problems wrong. Can someone point them

    asked by PETA on February 14, 2008
  25. chemistry

    my ques ok a coumpond containing 3atoms of carbon an 8 atoms ofhydrogen combined in reaction with oxy molecules the two end products of this equation are carbon dioxide co2 an water wat element should i look at first in balancing this question and wen i

    asked by andrea on May 12, 2008
  26. chemistry

    1. Need help Assigning oxidation numbers. Is it true that wehn looking at atoms in compounds from group 1 or 2 they are given the oxidization number which is the same as there charge example NaCl Na has an oxidization number of 1? But is this also true for

    asked by micheal on July 23, 2009
  27. Algebra

    Joyce combines 9 atoms of hydrogen and 3 atoms of nitrogen to make 3 molecules of ammonia. write a direct variation equation which relates atoms of hydrogen to atoms of nitrogen. How many nitrogen atoms does Joyce need to form ammonia molecules using 51

    asked by Andrea on November 27, 2012
  28. Bio

    1. An isotope is an atom of an element that varies in mass number due to variation in the number of: A. atoms. B. protons. C. neutrons. D. electrons. is it C 2, A covalent bond is: A. the attraction that one atom has for another atom. B. the attraction

    asked by Amy on July 10, 2013
  29. Science

    The energy from the Sun that reaches Earth is the result of which of the following processes, repeated many times in the core of the Sun? A) The nuclei of two atoms are combined to form a single atom with a larger nucleus. B) Molecules are rearranged to

    asked by Destiny on May 22, 2020
  30. Science

    Table salt has the chemical formula NaCl. Table sugar has the chemical formula C12H22O11. Which of the following is true? (1 point) Both compounds are held together by chemical bonds. Both compounds have the same density. Both compounds react with water.

    asked by Vanessa on January 28, 2016
  31. Chemistry please help

    State Dalton’s Postulates? In light of modern knowledge, what are the inaccuracies in Dalton’s Postulates? I know Dalton's postulates: -All matter consists of tiny, indivisible particles called atoms that cannot be created or destroyed -Atoms of one

    asked by Lena on February 19, 2012
  32. Chemistry

    The relative number of elements and compounds in a chemical equation are represented by either coefficients, subscripts, charges of phase symbols. I think it's coefficients, but is this right? My other question is that if you start a reaction with four

    asked by Khzyata on April 18, 2009
  33. Chemistry

    Can someone check these answers for me? I know some if not all are wrong, but I don't know which ones they are. -Substances are elements or compounds. Sometimes -Elements exist as molecules. Never -Compounds are molecules. Sometimes -Mercury is an element.

    asked by Cierra on October 3, 2007
  34. chemistry need help

    Determine the number of moles of each specified atom or ion in the given samples of the following compounds.( Hint: the formula tells you how many atoms or ions are in each molecule of formula unit.) a. O atom in 3.161x10^21 molecules of CO2 b. C atom in

    asked by bre bre on March 10, 2009
  35. chem

    when a chemical reaction takes place, the number of atoms of each element in the reactants (blank) the number of atoms of each element in the products

    asked by darrell on March 10, 2011
  36. biology

    1 mole of an element or compound contains 6.20 times 10 to the 23rd power atoms or molecules of the element or compound. 1 mole of an element or compound has a mass equal to its mass number (or molecular weight) in grams. For example, 1 mol of hydrogen gas

    asked by melly on July 15, 2011
  37. Science

    Can a molecule be an element? Molecules of most elements are made up of only one atom of that element. So, if a molecule is what you get when any atoms join together then no, a molecule can not be an element

    asked by Sue on November 11, 2015
  38. Science

    Different materials have properties that are desirable or undesirable for use in an artifical joint. Desirable (D)l Undesirable (UD) l Not Revelant (NR) 1.Chemically Stable (D) 2.Atoms can roll over each other (NR) 3.Consists of long molecules (UD)

    asked by Moe on September 22, 2018
  39. Chemistry

    A compound containg 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide (CO2) and water. What element should you look at first in balancing this equation?

    asked by MV on July 4, 2008
  40. chemistry

    what are 4 chemical properties of organic compounds?i know there non polar molecules and they tend to e soluble in non polar solvents,,but my homework says i need 2 more and i don't know what else..thanks :) Some organic compounds are non-polar and some

    asked by tameka on January 3, 2007
  41. chemistry

    how many molecules are in 5.5 moles of oxygen gas? How many atoms are in this quantity of gas? I used dimensional analysis and did: 5.5 mol. of oxygen x 6.02x10^23 molecules/1 mol of oxygen I got 3.3x^24 molecules of oxygen How do I find the # of atoms? I

    asked by ally on March 11, 2015
  42. science plzzz help

    From inside to out, describe the components of an atom. What makes one element's atoms differ from another element's atoms?

    asked by some girl on February 27, 2018
  43. chemistry

    A 48.0-g sample of an element has the same number of atoms as 6.00 g Na. What is the element?

    asked by Meg on November 21, 2007
  44. Chemistry

    Write the chemical formulas for the compounds containing each of the following: a) one calcium atom for every two iodide atoms. b) two nitrogen atoms for every four oxygen atoms. c) one silicon atom for every two oxygen atoms. d) one zinc atom for every

    asked by Melissa on July 1, 2010
  45. Chemistry

    An element has a body centred cubic structure with edge cell of 288 pm .The density of the element is 7.2 g/cm3.How many atoms are present in 208g of the element.

    asked by Raynold on November 8, 2012
  46. Science

    Plz Correct me!! Table salt has the chemical formula NaCl. Table sugar has the chemical formula C12H22O11. Which of the following is true? (1 point) Both compounds are held together by chemical bonds. Both compounds have the same density. Both compounds

    asked by Vanessa on January 28, 2016
  47. chemistry

    molecules of two different compounds contain the same number of atoms of each element but have different arrangement of atoms. which term correctly describes these two substances? a) isomers b) isotopes c) polymers d) none of the above

    asked by help on August 27, 2012
  48. chemistry

    molecules of two different compounds contain the same number of atoms of each element but have different arrangement of atoms. which term correctly describes these two substances? a) isomers b) isotopes c) polymers d) none of the above

    asked by help on August 27, 2012
  49. science

    Having a hard time understanding "representative particles". ie. which are atoms, compounds etc. For example, what is the representative particle for sodium fluoride? carbon monoxide? Atoms are the smallest unit of an element. Molecules are composed of two

    asked by mark on February 20, 2007
  50. science

    I wonder what atoms are and what molecules of two element/compounds are?

    asked by didi on November 23, 2009
  51. Science

    Helloo.. i got a worksheet about compounds,elements andnumber of elements. it tells me to list the elements and number of atoms found in each of the compounds and i don't understand how to do get the elements and the # of atoms in the equation.. PLease

    asked by Hannie on July 16, 2008
  52. science

    IDK these help pls 1. Which of the following is a compound? A. O2 B. NH3 C. H2O+NaCl D. N2 2. What is the difference between compounds and mixtures? A. Compounds contain only one element; mixtures contain two or more elements. B. Compounds contain two or

    asked by hawseefoo on October 3, 2018
  53. chemistry

    How do I calculate the number of atoms in a compound (not an element)? I have the mass of the amount of substance, and the molar masses. How do I do this? Is this the same as calculating the number of molecules/ formula units? Also, I know the number of

    asked by pinkmercy on November 19, 2012
  54. CHEMISTRY

    what is the symbol for chromium (II) sulfate? You mean the formula? CrSO4 yes! thanx!!!!!! do u know how to find the number of molecules or atoms in a mole? The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02

    asked by INEEDHELP!!! on December 4, 2006
  55. science

    How do you find out the number of atoms in a chemical formula? Count up the number of atoms in the formula. If there is a subscript n after an element sytmbol, there are n or those atoms in the molecule. If there is no subscript, there is only one atom of

    asked by stephii on June 12, 2007
  56. Chemistry

    How do you find out the number of moles in a certain amount of grams of a element or compound. After that, how do you find the number of atoms/molecules in that element or compound. Thanks grams/molar mass = # mols There are 6.02 x 10^23 molecules in a mol

    asked by Slice on November 30, 2006
  57. chemistry

    Isotopes (select one or more): are chemicals that react only with protons. for an element have the same chemical properties. are atoms of an element that differ in the number of protons. are atoms of an element that differ in the number of neutrons. for an

    asked by ray on December 12, 2011
  58. Chemistry

    I have realized I don't understand Avagado's number at all My book shows me this diagram instead of just providing a simple formulas that makes no sense at all here is what I have made sense of so far (6.022 x 10^23 atoms/mol)(mass of element) = molecular

    asked by Kate on July 3, 2010
  59. Biology

    4. The difference between an atom and and element is a. an element is made of atoms b. atoms are made of elements c. atoms are held together by covalent bonds d. none of the above C? 6. Which of the following is NOT an organic compound? a. ATP molecule b.

    asked by mysterychicken on January 20, 2010
  60. Biology

    4. The difference between an atom and and element is a. an element is made of atoms b. atoms are made of elements c. atoms are held together by covalent bonds d. none of the above C? 6. Which of the following is NOT an organic compound? a. ATP molecule b.

    asked by mysterychicken on January 21, 2010
  61. chemistry

    Determine the number of moles of each specified atom or ion in the given samples of the following compounds.( Hint: the formula tells you how many atoms or ions are in each molecule of formula unit.) a. O atom in 3.161x10^21 molecules of CO2 b. C atom in

    asked by bre bre on March 8, 2009
  62. How do I calculate the number of atoms in a compou

    I have the mass of the amount of substance, and the molar masses. How do I do this? Is this the same as calculating the number of molecules/ formula units? Also, I know the number of atoms for each element in the compound (It made me calculate that before)

    asked by pinkmercy on November 19, 2012
  63. Chemistry (The Composition of an Atom)

    In 1808, John Dalton wrote his atomic theory of matter. The following is a list of points from that theory. If it is still considered true today, label it true. If it is not considered true today, label it false. 1)Atoms cannot be subdivided. 2)Atoms

    asked by Andy on April 14, 2011
  64. biology

    Allegra is a blockbuster allergy medication that generated over $1.8 billion in global sales in 2004. Allegra, or Fexofenadine, decreases allergy symptoms by inhibiting the action of histamines. Histamines are naturally occurring molecules that are

    asked by selly on March 12, 2013
  65. chemistry - ozone

    hi, can anybody tell me the molecules that destroy ozone? i need a fair few molecules to write in my homework...thanks! The main species responsible for destroying ozone in the stratosphere is Cl atoms. Br atoms are also very effective but there aren't

    asked by harshini on June 26, 2006
  66. physical science

    calculate the molar mass ofthe substance. divide it by Avogadros number (6.02x10 to 23 power) .)Hydrogen2 2/(6.02 x 10^23) = ?? hun i don't get it the teacher said first H2x1.00 and then (6.02xio^23) but i still don't get it can you help? I assume you

    asked by Jasmine on October 20, 2006
  67. chem

    For which element would you expect isotope effects to be of the greatest importance in CHEMICAL processes? a.H b.He c.Li d.B This problem could be interpreted many different ways and come up with different answers, I suppose. In the context of number of

    asked by nivi on April 23, 2007
  68. chem

    How many atoms are there in the following problems? which one has the most number of atoms? a. 5 molecuels (NH4)2S b. 9 molecules H2O2 c. 11 molecules O3

    asked by chemdummy on October 30, 2012
  69. chem

    How many atoms are there in the following problems? which one has the most number of atoms? a. 5 molecuels (NH4)2S b. 9 molecules H2O2 c. 11 molecules O3

    asked by chenchen on October 30, 2012
  70. Chem

    How many chlorine atoms are in 5.0 g of C2H3Cl3O2? What mass of C2H3Cl3O2 would contain 1.0g Cl? There are 6.02 x 10^23 atoms in a mole of anything. Calculate the molar mass of your compound, that mass will contain 6.02 x 10^23 molecules of that material

    asked by Min on December 9, 2006
  71. chemistry

    elements x and y are from group 7 in the periodic table. x is a liquid at rtp, while y is a solid at rtp. which statements are correct? 1) atoms of y have more protons than atoms of x 2) molecules of y have more atoms than molecules of x 3) y displaces x

    asked by Marrion on October 10, 2009
  72. science

    radioactive decay occurs when atoms a) lose mass b) join with atoms of another element c) break down to form atoms of another element d) are exposes to chemical weather

    asked by victoria on December 13, 2013
  73. science

    plz check Radioactive decay occurs when atoms - lose mass - join with atoms of another element*** - break down to form atoms of another element - are exposed to to chemical weathering i think B

    asked by Anonymous on December 11, 2018
  74. Chemistry

    a) Fe2O3 b) Ca3P2 How many atoms of each element are contained in 200 g of each of the above compounds?

    asked by Jack on February 1, 2020
  75. science

    what kinds of atoms form the molecules for each element...please help me

    asked by Katherine on January 20, 2010
  76. Science

    When elements in the same group form molecules, the number of outer-shell electrons involved is the same and so the number of bonds forming the molecule is the same roo. Eg. Every element in group 2 (groupII) is a solid metal. When these elements bond with

    asked by Ghumaisha on March 14, 2020
  77. Chemistry

    Which letter of the term that is NOT a representative particle of a substance. a)molecule b)atom c)grain d)formulaunit Was ist der "Grain"? what is the representative particle for the substance moelcular compounds? an can you show me how you got the

    asked by Chris on February 2, 2007
  78. Science

    Can an element be separated from a compound? Can an element form a compound? The reaction of zinc metal and hydrochloric acid creates hydrogen gas, an element. if we create this element in a tube what property of this element requires us to keep the tube

    asked by Roma on February 16, 2014
  79. CHEMISTRY

    list three differences between molecular and ionic compounds, and explain how they relate to the differences in bond types.....how do i relate to the differences in bond types? List the differences and we'll talk about how they relate to the bond type. 1.

    asked by INEEDHELP!!! on December 6, 2006
  80. science

    element Q forms compounds with the element X and with element Z write the formulas for these 2 compounds?

    asked by Chelsea on May 5, 2008
  81. Physics Help Please

    Scientists at Oak Ridge National Laboratory confirmed the existence of element 104 by creating 3000 atoms of it. If radioactive decay caused the number of atoms to drop by half within 4.0 s, how many atoms were left after 12 s? Show work please! Thank you!

    asked by Kim on May 2, 2015
  82. chemistry

    calculate number of atoms in 4.67 mol of Ca(NO3)2 I got: 2.81 X 10^24 C atoms or should it be 28.11 x 10^23 C atoms? 5.62 X 10^24 N atoms or should it be 9.34 x 10^23 N atoms? 1.69 x 10^25 O atoms....but are you allowed to do ^25 or should it be 168.7 X

    asked by Sarah on May 23, 2008
  83. physics

    Oxygen molecules contain two oxygen atoms, and carbon dioxide molecules contain one atom of carbon and two atoms of oxygen. How does the total number of molecules in 1 liter of oxygen compare with the total number of atoms in 1 liter of carbon dioxide if

    asked by Loui on April 24, 2011
  84. Chemistry (Check)

    Fill In the Blank Compounds that are formed when two or more atoms combine to form molecules are called __________. is it diatomic molecule. yes.

    asked by Bryan on November 28, 2006
  85. chemistry.

    They are__________Mol of carbon atoms in 4 mol of Dimedthysulfoxide A: 2 B: 6 c: 8 D: 4 E: 3 My answer is C:8 but can any one help me with the method to show the right answer. 2. There are ___________Sulfur atoms in 25 molecules of c4H4S2. My answer is

    asked by Richard on September 12, 2009
  86. Quick chemistry help

    How would I find the number of atoms in this mole statement? 12 molecules chlorine gas=_______ atoms of Cl

    asked by Anonymous on February 26, 2015
  87. Science

    Lithium atoms, like hydrogen atoms, have only a single electron in their outer shells, yet lithium atoms do not join together to form Li2 molecules the way hydrogen atoms form H2 molecules. Instead, lithium is a metal with each atom part of a crystal

    asked by Sheryl on October 22, 2011
  88. Chemistry

    'Would the probability factor in the rate equation be greater or lower if the particles colliding were individual atoms instead of molecules? ' I want to say it would be lower because atoms have less kinetic energy than molecules due to their lesser mass,

    asked by SarahF275 on January 20, 2018
  89. chemistry

    Calculate the following quantities. (See the periodic table.) (a) mass, in grams, of 2.54 10-2 mol of CdS g (b) number of moles of NH4Cl in 90.0 g of this substance mol (c) number of molecules in 5.081 10-2 mol C6H6 molecules (d) number of O atoms in 4.72

    asked by Anonymous on August 2, 2012
  90. Kelsie

    name the element wsith the atomic number z= 15 and the atomic mass number 31. How many electrons does the neutral of this lement have? How many neutrons does the neutral atoms of this element have? I know the element with the atomic number of 15 and atomic

    asked by CHEMISTRY on November 8, 2010
  91. binary compounds!

    based on only differences in electro negativity, what compounds would be the most strongly ionic of all binary compounds? The compound consisting of the most electropositive element with the most electronegative. The most electropositive element is at the

    asked by penny on June 17, 2006
  92. physics

    need five differences between compounds and molecules...... got only one that is ;A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements.

    asked by leena on February 3, 2014
  93. physics

    Two radioactive sources X and Y have half-lives of 3.0 hours and 2.0 hours, respectively. The product of the decay is a stable isotope of the element Z. Six hours ago a mixture contained the same number of atoms of both X and Y, and no other atoms. What

    asked by Valeriya on February 4, 2019
  94. chemistry

    how many atoms of iron are in .0750 moles of the compound Iron(III) oxide? Fe2O3 my guess is .375 am I right .750/2=.375 No, don't guess. The molar mass of Fe2O3 is approximately 159. You should look up the molar mass and use the exact number. 159 grams (1

    asked by mike on May 14, 2007
  95. Chemistry

    UMM.. I keep coming up with the wrong answer? How do I calculate this? 1. Calculate the number of Li atoms in 9.9 moles of Li. Express your answer using two significant figures. 2. Calculate the number of CO2 molecules in 3.13×10−2 mole of CO2.

    asked by Jennie on February 27, 2015
  96. college

    A gas containing both hydrogen molecules (each molecule contains two hydrogen atoms) and helium atoms has a temperature of 300 K. How does the average speed of the hydrogen molecules compare to the helium atoms?

    asked by Anonymous on October 25, 2013
  97. PNU

    An element has a body-centered cubic(bcc) structure with a cell edge of 288pm the density of the element is 7.2g/cm3. How many atoms are present in 208g of element

    asked by abeer on February 17, 2015
  98. chemistry

    Covalent bonds are formed when two atoms share electrons. The pairs of electrons which are shared between atoms and hence number of covalent bonds, can be represented by the number of lines drawn between the symbols for the atoms. For example, a single

    asked by trigger on December 30, 2008
  99. Science

    Table salt has the chemical formula NaCl. Table sugar has the chemical formula C12H22O11. Which of the following is true? (1 point) Both compounds are held together by chemical bonds. Both compounds have the same density. Both compounds react with water.

    asked by Del Rey on January 28, 2016
  100. Chem

    From the information below, identify element X. a. The wavelength of the radio waves sent by an FM station broadcasting at 97.1 MHz is 30.0 million (3.00 X lo7) times greater than the wavelength corresponding to the energy difference between a particular

    asked by Dianne on March 29, 2007