1. **CHEM

    Place the following elements in order of Decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium. would the correct ranking then be: Cs, Sr, Te, Se, Br, Ar ??? or am I still way off??
  2. CHEM**

    I just have 2 other questions that I just want to make sure on: Place the following elements in order of decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium. (Te, Br, Ar, Cs, Sr, Se) ~~(or...the correct ranking cannot be determined)~~ I think ...
  3. Atomic Size

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  4. Chemistry

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  5. Chemistry

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  6. I don't understand this chemistry problem?

    The question reads: Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur. I looked this up on a periodic table and my answer was: Rb, Se, Ca, Cl, F, S. This is still marked wrong, and I don't know why.
  7. Chem - Elements

    I need help on identifying four elements. 1. a member of the same family as oxygen whose most stable ion contains 54 electrons. (Sulfur?) 2. member of alkali metal family whose most stable ion contains 36 electrons. (Cesium??) 3. noble gas with 18 protons in nucleus (argon?) 4...
  8. **CHEM**

    Arrange the following elements in order of decreasing atomic radius: Cs, Sb, S, Pb, Se *(list from largest to smallest...or..."the correct ranking cannot be determined") ***I think the answer 'should be', from largest to smallest: ***Cs, Pb, Sb, Se, S***???? Am I correct in my...
  9. Chemistry

    Sort the following elements by electron affinity, from most positive to most negative EA value: bismuth, chlorine, helium, cesium, and tellurium.
  10. Gps

    Arrange in order of increasing atomic size use appropriate < > -= symbol to separate substances in the list 1. The period 2 elements Be,B and N The group 4A elements Sn,Si, and Pb
  11. Chem

    Rank thefollowing elements in order of decreasing atomic radius. N, B, Be, Li? I thought it was N, B, Be, Li
  12. Chemistry

    Bromine has two naturally occurring isotopes. Bromine-79 has a mass of 78.918 amu (atomic mass unit) and is 50.69% abundant. Using the atomic mass reported on the periodic table, determine the mass of bromine-81, the other isotope of bromine.
  13. Chemistry

    A neutral molecule is identified as a tetrafluoride, XF4, where X is an unknown atom. If the molecule has a dipole moment of 0.63 D, can you give some possibilities for the identity of X? (Select all that apply.) sulfur nitrogen oxygen polonium phosphorus selenium tellurium ...
  14. the periodic table

    combine the chemical symbols for each of the following elements to spell words. carbon +argon =____.chlorine + oxygen +selenium=----+---- +----- =------ .i have 10 questions like these .please help me
  15. Chemistry

    12) Naturally occurring argon is composed of 0.3365% of 36Ar (atomic mass, 35.9675 u), 0.0632% of 38Ar (atomic mass, 37.9627 u), and 99.6003% of 40Ar (atomic mass, 39.9624 u). Use these data to calculate the average atomic mass of argon.
  16. Chemisty !!

    (a) Why do the densities of most liquids increase as they are cooled and solidified? How does water differ in this regard? (b) Rank the following compounds in order of decreasing surface tension at a given temperature, and explain your ranking. CH3CH3, CH3OH, H2C=O (c) Rank ...
  17. Chemistry

    1) What is the atomic # for selenium? 34 2) Write the full electron configuration for selenium following the (n+l) rule? I am not sure what is meant by n+l 3) write the electron configuration, grouping electrons by their "n" values. [Ar]3d10 4s2 4p4 Are these correct? 4) What ...
  18. science

    1. When Mendeleyev arranged the elements into the periodic table, he found that elements with fell into groups on the table A. the same mass B. similar size C. Similar properties D. The same color 2. Every element has its own atomic number. The atomic number is the number of ...
  19. chemistry

    Examine the elements listed below. nitrogen (N), phosphorus (P), arsenic (As) Which of the answer choices accurately describes a common property of these elements? they have the same amount of atomic mass they have the same amount of reactivity they have the same number of ...
  20. Chemistry

    Bromine has two isotopes, Br- 79 and Br- 81. The relative atomic mass of bromine is 79.9. CALCULATE THE PERCENTAGE of Br-79 atoms in a sample of bromine. PLease help i'm really stuck
  21. Modern Chemistry

    Bromine has two naturally occurring isotopes. Bromine-79 has a mass of 78.918 amu and is 50.69% abundant. Using the atomic mass reported on the periodic table, determine the mass of bromine-81, the other isotope of bromine.
  22. Chemistry

    bromine has two isotopes Br,79 and Br-81 the relative atomic mass of bromine is 79.9 calculate the percentage or br 79 atoms in a sample of bromine show all working out with all equations used and no abbreviations please
  23. chemistry

    1) Rank the elements, aluminum, sodium and phosphorus, in order of decreasing conductivity. 2) Rank the elements aluminum, gallium, and boron in order of decreasing conductivity
  24. chem

    Bromine consists of two major isotopes with the following percent abundances and atomic masses: 79Br (50.54% and 78.918 amu) and 81Br (49.46% and 80.916 amu). Calculate the average atomic mass of bromine.
  25. science chem

    give one example of two elements that would be placed incorrecty if they were in order of their relative atomic masses. and explain why placing these two elements like this would not be correct. Pleasw could someone help me. Co/Ni is one. Ar/K is a second one. I will leave it ...
  26. physics

    Argon is a monatomic gas whose atomic mass is 39.9 u. The temperature of eight grams of argon is raised by 95 K under conditions of constant pressure. Assuming that argon behaves as an ideal gas, how much heat is required?
  27. chemistry

    Given the following Unknown atoms with their respective atomic numbers, X; Atomic number 19, Y; Atomic number 15, a. Deduce the identities of the elements X and Y. b. What are the mass numbers of the two elements X and Y? c. Calculate the number of Neutrons in the respective ...
  28. chemistry

    1. A 12.5843g sample of zrbr4 was dissolved and after several steps all of the combined bromine was precipitated as ArBr. The silver content of AgBr was found to be 13.12160g Assume the atomic masses of silver and bromine to be 107.868 and 79.904.what value was obtained for ...
  29. AP Chemistry

    A 12.5843 g sample of ZrBr4 was dissolved and, after several chemical steps, all of the combined Bromine was precipitated as AgBr. The silver content of the AgBr was found to be 13.2160 g. Assume the atomic weights of silver and bromine to be 107.870 and 79.909 respectively. ...
  30. Chemistry Help!!!!

    for each of the following pairs of elements, give the correct molecular formula, explain how you arrived at this answer( you may use the Bohr model notation, or the orbital model notation, or explain linguistically) and note whether the bonding is covalent or ionic. ( I tried ...
  31. Math

    The element strontium-90 is radioactive. The percent of strontium -90, A(t), left in a sample can be modelled by the half-life function A(t) = A0 (1/2)^t/29, where t represents the time, in years, after the initial time, and A0 represents the initial amount, 100% of the ...
  32. Chemistry

    The isotopes of argon have the following relative abundances: Ar-36 0.34% Ar-38 0.06% Ar-40 99.66% Estimate the average atomic mass of argon. How would I go about doing this?
  33. chemistry

    Table of enthalpy of solution for selected cesium salts Compound and ΔsolH kJ mol-1: - Cesium bromide: 25.98 - Cesium iodide: 33.35 - Cesium chloride: 17.78 - Cesium fluoride monohydrate: -10.46 - Cesium fluoride sesquihydrate (ยท1.5H2O): -5.44 Data taken from CRC ...
  34. chemistry

    consider the elements;Na,Mg,Cl and F.state with reasons,which element has the highest electronegativity. 2. Arrange with reasons, the elements in decreasing order of ionization energy
  35. Chemistry

    Five grams of sodium are combined with unlimited bromine. How many moles of bromine are used up? How many liters of bromine would be used if the reaction took place at STP? My answer: .1088 mole Br2 and 2.44 L Br2
  36. Chemistry

    Five grams of sodium are combined with unlimited bromine. How many moles of bromine are used up? How many liters of bromine would be used if the reaction took place at STP? My answer: .1088 mole Br2 and 2.44 L Br2
  37. chemistry

    Helpful steps? Calculate the predicted atomic radius for potassium, K, given the atomic radius of rubidium, Rb, (0.247 nm) and cesium, Cs, (0.265 nm).
  38. CHEMISTRY

    Rank these elements according to first ionization energy.. I ranked them like this Ar Cl S P Si Al Mg Na but then it tells me that two elements should move up one spot in the ranking because of stable electrons configurations. Which ones would be moved up and why?
  39. Chemistry

    What is the trend in atomic size in the series of Group IIA elements Be through Ra?
  40. Science

    Tellurium is a metalloid. How many valence electrons does tellurium have? 3 4 5 6
  41. chem

    Consider the following chemical equilibrium: SO3(g) --> SO2(g) + 1/2 O2(g) and Delta H = 98.9J i. adding oxygen gas ii. compressing the system at constant temperature iii. adding argon gas iv. removing sulfur dioxide gas v. decreasing the temperature Which of the above (i-v...
  42. Physics

    Three spheres are made from the same material, but each has a different size and temperature. The radii of spheres A, B, and C are 1.5R, R, and 1.25R, respectively. Which of the following choices gives the correct ranking of the spheres in order of least radiant energy emitted...
  43. Chemistry

    Bromine has two isotopes, Br- 79 and Br- 81. The relative atomic mass of bromine is 79.9. CALCULATE THE PERCENTAGE of Br-79 atoms in a sample of bromine. PLease help i'm really stuck Someone said: The total for 79 and 81 is 100% and the total for fraction is 1, so let X = ...
  44. Science

    What were Mendeleev's reversals?How did Henry Moseley explain them? Mendeleev thought the periodic table was in order of atomic mass. Mosley determined that atomic number was the correct order. http://www.chemistry.co.nz/henry_moseley.htm
  45. physical science

    Thanks got through all but one Element P has an atomic number of 92 and atomic mass of 238. Element s has 92 protons and 143 neutrons. atomic number and protons are the same would htese two elements be an isotope or different elements
  46. Final Exam- Honors Physical Science

    how can you determine the number of protons, electrons,neutrons, atomic number, and the atomic mass of an element using the periodic table? Atomic mass is given in the table, as well as the atomic number and atomic mass number. Atomic number is the number of protons, which is ...
  47. Chemistry

    Please help me arrange these elements in decreasing order of metallic property. I, Mg, Al, Rb, Ca Thank You
  48. Chemistry

    Help arrange these elements in decreasing order of metallic property I, Mg, Al, Rb, Ca
  49. Chem

    Order the elements S, Cl, and F in terms of increasing atomic radii. I thought the answer was F, S, Cl, but the answer key said it was S, F, CL Why? AR decreases from left to right. Sulfur has one more energy level, so shouldn't its atomic radii be greater than fluorine?
  50. CHEM

    Arrange the elements in decreasing order of the number of valence electrons Br,S,Sb,Sr,F,Mg,I,Ca,Na,Kr,Xe,Bi,Ge,Ga,K
  51. Finite Math

    Please help with this problem. In a student writing contest with 25 entries, 3 essays are selected for first, second, and third place awards and 5 are selected for honorable mention. How many ways can this be done? Thanks. Ok Gen, for the first place there are 25 choices, for ...
  52. chemistry

    which of the following is true regarding the transition elements? A. Multiple oxidation states resulting from the involvement of d electrons in bonding is a characteristic of transition elements. B. Most transition elements have lower melting and boiling points than the main ...
  53. 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 from aqueous solutions...
  54. chemistry

    why does atomic size decrease cross a period? why does atomic size increase down a group?
  55. Chemistry

    7. Which of the following is true? A. Cesium is the most active group 1 metal, because its valence electron is held more tightly than the others in the same group. B. Group 1 elements are more reactive than the group 2 elements because they have more valence electrons to lose...
  56. chem help

    Arrange the following elements in order of increasing atomic radii. Sr, Rb, Sb, I, In
  57. Physics

    I am confused, selenium Se, is on the periodic table, but does it combine with other elements on the periodic table? I want to say no because it is a gas. Is that correct.
  58. chemistry

    Which of the following is true? A. Group 1 elements are more reactive than the group 2 elements because they have more valence to lose. B.Lithium is the least reactive element in group, because its valence electron is held more tightly than the others in the same group. C. ...
  59. Chemistry

    What is the valency of selenium in hydrogen selenide? Consider what selenium's group is in the periodic table. There is oxygen and sulfur, right? Selenium will the same as those. The all have the same basic formula with hydrogen. What's that very common substance that contains...
  60. Chemistry

    1) What is the charge on the ion that Selenium forms in an ionic compound? I am not sure about this. 2) What noble gas is isoelectronic with this ion. I was thinking Krypton because it is a noble gas and it is the closest to Selenium but I am not sure. 3) What other ions are ...
  61. chem

    Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing strontium-90 to decrease to 58.32% of its initial activity? The half-life of strontium-90 is 2.88e1 years.
  62. Chemistry

    How is it possible that the atomic number increases in order, yet the atomic masses do not? A. There is no relationship between the atomic number and mass of the atom. B. The masses of the protons for Te, I, and Xe have slightly different masses. C. Since the numbers of ...
  63. SCIENCE

    ORDER OF INCREASING ATOMIC SIZE: Cs, Li, and Rb
  64. chemistry

    Rank the following elements by electron affinity, from most positive to most negative EA value: tellurium, bismuth, neon, sodium, iodine i tried Te, Bi, Na, I, Ne and it was incorrect.
  65. Science

    Does Francium or Cesium have the greatest atomic radius? Thank you
  66. chemistry

    Based on position in the periodic table and electron configuration, arrange these elements in order of decreasing E_ i1
  67. chemistry

    Evaluate the statement. Bromine (Br) is a halogen. Given the information in the statement, what can be inferred as true about bromine? bromine tends to form covalent bonds when in a chemical reaction with metals bromine has seven electrons and seven protons bromine does not ...
  68. CHEMISTRY

    a gas mixtuer consists of equal masses of methane(molecular weight 16.0) and argon (atomic weight 40.0) if the partial pressure of argon is 26.6 kPa, what is that of methane in the same units? 10.7 26.7 66.7 34.1 I am going with 26.7 Do you agree and why please Thanks Andy
  69. chemistry

    Boron, germanium, aluminum, silicon and antimony are all semimetals right? or am i wrong on this? i don't think aluminum. Antimony, aresenic, boron, germanium, selenium, silicon, tellurium. double check though.
  70. Chem

    Na P Ca Br arrange in incresing order of atomic size
  71. geometry

    List the following elements in proper set notation. Place the elements in numerical order within the set. * 0 * 1 * 123 * 4 * 34
  72. geometry

    List the following elements in proper set notation. Place the elements in numerical order within the set. * 0 * 1 * 123 * 4 * 34
  73. geometry

    how do you do list the following elements in proper set notation. Place the elements in numerical order within the set. *0*123*4*34* 1
  74. Chemistry

    Rank the ions in order of decreasing size. Sr2+, Ba2+, Cs Cs>Ba>Sr
  75. chemistry

    Dr bob can you help with my last question for tonights home work please A gas mixture consists of equal parts of methane(molecular weight 16.0) and argon (atomic weight40.0). if the partial pressure of argon is 26.6 kPa what is that of methane in the same units? 10.7 26.7 66.7...
  76. chem

    Cesium-137 is part of the nuclear waste produced by uranium-235 fission. The half-life of cesium-137 is 30.2 years. How much time is required for the activity of a sample of cesium-137 to fall to 25.1 percent of its original value?
  77. Chemistry

    Radioactive decay is first order in the decaying isotope. For example, strontium-90 contained in fallout from nuclear explosions decays to yttrium-90 and a beta particle. Write the rate law for the decay of strontium-90. Can you please take me step by stem through this problem?
  78. Science help

    For each of the following what type of smallest particle would exist? explain your reasoning? a.) strontium B.) CaCl2 C.) CCl4 D.) SO2 E.) helium F.) bromine G.) MgO Thanks :):):):)
  79. Chemistry

    As you go across the period of the periodic table, you are increasing the atomic number while decreasing the atomic radius, but what causes this trend?
  80. Chemistry

    1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...
  81. Chemistry

    1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...
  82. Chemestry 095

    Write the electron configuration for the following ground state atoms and ions. strontium+2 ion; iron element; selenium -2 ion; gallium +3 ion; and tin element.
  83. CHEM Periodic Trends

    Each of the statements below attempts to explain why some periodic property varies predictably among elements in the periodic table. Determine if each statement is true or false. Within a family, elements with higher atomic numbers have higher electronegativity because the ...
  84. Nuclear Physics

    A meteorite has landed at UOIT! Chemical analysis shows that it contains 1 gram of potassium and 1E-5 grams of argon, assumed to be present entirely from the decay of K-40. Assuming that no argon has escaped the meteorite, estimate the age of the meteorite. Data given: Natural...
  85. Science

    What conclusion can be drawn about the relationship between the arrangement of elements on the periodic table and the patterns observed in their priorities? A. Properties of elements are related to atomic numbers. B. Properties of elements are related to ductility. C. ...
  86. chemistry

    What mass of cesium bromine must be added to a 0.500 liter of water (d=1.00 g/ml) to produce a 0.981m solution? what are the mole fraction and mass percent of CsBr?
  87. Chemistry

    I just need help with this one question, and then once I know how to do the steps, I think can do the others. --- The average atomic mass of argon is 39.95 u. Natural argon contains three isotopes: Ar-36 (35.967 u), Ar-38 (37.962 u)& Ar-40 (39.962 u). If the isotopic abundance...
  88. Chemistry

    Arrange the following cations in order of decreasing size :Ra2+,Sr2+,Ca2+,Ba2+.Also explain it.
  89. algebra 2

    Apparently i got this wrong, but my teacher is giving me a chance to redo. The question was to put these numbers in decreasing order. _/13, pi, 1.3, -0.7, -8/5 (and i put them in this order) She gave me a 0/2 and said think about how you would place them on a number line. Any ...
  90. science

    1) What conclusions can be drawn about the relationship between the arrangement of elements on the periodic table and the patterns observed in their properties? :Properties of elements are related to atomic numbers.*** :Properties of elements are related to ductility. :...
  91. math

    Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t)=(.98)^t (b) Estimate the half-life of strontium. (c) If presently...
  92. chem1 WORD PROBLEM!!

    lead has an atomic number of 82;iron has an atomic number of 26; and copper has an atomic number of 29.how do the charges of the nuclei of these 3 elements compare?
  93. Chemistry

    Which trends are observed when the elements in Period 3 on the Periodic Table are considered in order of increasing atomic number? (1) The atomic radius decreases, and the first ionization energy generally increases. (2) The atomic radius decreases, and the first ionization ...
  94. Chemistry

    The standard atom for the atomic masses of all the elements is the atom of carbon which has 6 protons and 6 neutrons (12C) and is assigned the atomic mass of exactly 12. Under this standard, the atomic mass of iron, atomic number 26, is 55.845 u and the atomic mass of gold, ...
  95. science,physics,chemistry

    According to our theory atomic size should increase in groups from top to bottom but in group 13 Aluminium has atomic radius 143 pm and Gallium has atomic radius 135 pm which is less WHY??????
  96. Chemistry

    We did a flame test today to see what substances produce what colors when burned. Can you please explain... Why each of the different elements have a different atomic emission spectrum? Would the flame tests be useful for detecting individual elements present in a mixture of ...
  97. Chemistry

    Of the 3 elements fluorine, nitrogen, and carbon, what is the atomic number of the one that has the largest atomic radius?
  98. Chemistry

    Of the 3 elements nitrogen , oxygen , and aluminum, what is the atomic number of the one that has the smallest atomic radius?
  99. physics

    Bees often work together for the greater good of the hive. Sometimes they can get excess charge on them. Four pairs of bees, which can be represented as identical, conducting spheres, bump into each other in the hive. Rank the bees in the order of the size of the magnitude of ...
  100. Physics

    Bees often work together for the greater good of the hive. Sometimes they can get excess charge on them. Four pairs of bees, which can be represented as identical, conducting spheres, bump into each other in the hive. Rank the bees in the order of the size of the magnitude of ...
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