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

70,934 results
  1. chemistry

    For the following reaction KClO2->KCl+O2 assign oxidation states to each element on each side of the equation. Reactants K=? Cl=? O=? Which element is reduced? I got K=5, Cl=-1, and O=-4 . The element that reduced is K, but its says its wrong. Help,

  2. Science

    1.)​CaCO3→CO2​+CaO A scientist heats 30 grams of calcium carbonate (CaCO3) in the chemical reaction shown. What is the total mass of the products?(1 point) A.)10 grams B.)15 grams C.)60 grams

  3. Physical Science

    Which condition must be met in order for an equation to be balanced? A. The elements in the reactants are the same as the elements in the products. B. There are fewer elements in the reactants than there are in the products. C. The number of atoms in the

  4. Science

    1.Suppose 10 atoms of carbon (C) react with 20 atoms of oxygen (O). According to the Law of Conservation of Matter, how many atoms will there be in the product of this reaction?(1 point) A. 20 B. 30*** C. 10 D. 15 2.Which procedure could be used to

  5. biology

    Which of the following would differ if you compared the same reaction taking place with and without an enzyme? a. the chemical energy of the reactants. b. the chewmical energy of the products. c. the energy required to start the reaction. d. the overall

  6. Science

    Which statement is true regarding a chemical reaction?(1 point) A. Even if the total number of atoms changes, mass may not be conserved in the reaction. B. The total number of atoms changes, so mass is conserved in the reaction. C. The total number of

  7. biology

    1. Suppose you plant a seed and observe that a tree of large mass grows from it. The tree achieves a final mass that changes very little for years afterward. Which of the following is true about the tree? (1 point) Both anabolic and catabolic reactions

  8. 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 ?

  9. Science/Chemistry

    Cobalt has a mass number of 59 and an atomic number of 27. A student wants to create a model of a cobalt atom. Which statement about the model is correct? The model should show 27 protons and 32 neutrons. The model should show 27 protons and 27 neutrons.

  10. 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

  11. SCIENCE IMMEDIATE HELP PLZ

    in which chemical reaction is the number of atoms in the reactants the same as the number of atoms in the products? a. Zn+2HCI->H2+ZnCI2 b. CH4+O2->CO2+2H2O c. CO2+CH2OH+O2 d. Li2CO3->LiO+CO2

  12. chemistry

    Examine the scenario. Chemical Reaction A and Chemical Reaction B involve the same two reactants. Chemical Reaction A is performed in a hot container, while Chemical Reaction B is performed in a cold container. Which of the answer choices correctly

  13. 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

  14. chemistry

    elements below, indicate how each elements’ valence electrons act in a chemical reaction. Insert an L if an element loses electrons, a G if the element gains electrons, an E if the element can either lose or gain electrons, and a U if the element is

  15. 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

  16. Chemistry

    The following chemical reaction takes place in aqueous solution: MnBr2(aq) + 2KOH (aq) → Mn(OH)2 (s) + 2KBr (aq) Write the net ionic equation for this reaction.

  17. 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

  18. 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

  19. Physical Science

    Which of the following statements are true about chemical reactions? Check all that apply. A. Reactants are on the right when writing a chemical reaction. B. Products are produced in a reaction. C. Reactants are present at the end of a reaction. D.

  20. 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

  21. Chemistry

    How is the law of conservation used to balance a chemical equation? In a chemical equation, the products formed have the same atoms as the original reactants; however, the atoms may be rearranged with different subscripts. The law of conservation of mass

  22. 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

  23. bio

    Assignment: Photosynthesis and Cellular Respiration Energy acquisition is essential for all life. Whether the organism is classified as plant or animal, single-celled or multi-cellular, the exchange of energy and the formation of products consist of a

  24. Science

    The reactants side of an equation is shown. How many silver atoms should the products side of the equation have after a chemical reaction? 2 A g 2 O ⟶ ? 3 2 1 4 I was thinking 2 but im not sure. A water molecule is made up of two hydrogen (H) atoms and

  25. Chemistry

    1. For the reaction 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases? A. Shift to the right B. Shift to the left C. Doubles D. Does nothing E. Halves 2. if an equilibrium reaction shifts to the right when the

  26. Physical science

    What happens when an atom gives up loosely held valence electrons to another atom? A. The two atoms form a mixture. B. A chemical bond forms between the two atoms. C. A chemical compound splits into separate elements. D. The two atoms combine to create an

  27. Science

    1. Which of the following is true about photosynthesis? A) It is an exothermic reaction. B) It is an endothermic reaction.** C) It produces carbon dioxide. D) It occurs in animals. 2. Atomic theory is A) subject to change if new information is discovered.

  28. 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

  29. Pre-Calculus

    Consider the chemical reaction aC2H6 + bCO2 + cH2O → dC2H5OH, where a, b, c, and d are unknown positive integers.? The reaction must be balanced; that is, the number of atoms of each element must be the same before and after the reaction. For example,

  30. science

    2Al+3H2SO4--> Al2(SO4)3+3H2 a.)determine the oxidation number of each element in both the reaction and products of this oxidation-reduction reaction of aluminum and sulfuric acid. b.) what element is oxidized in this reaction? c.) what element reduces in

  31. physical science

    in a balanced chemical equation the mass of the reactants is equal to the? a. atoms in a molecule b. atomic mass of the elements c. volume of the reactants d. mass of the products

  32. Physical science

    What happens when an atom gives up loosely held valence electrons to another atom? A. The two atoms form a mixture. B. A chemical bond forms between the two atoms. C. A chemical compound splits into separate elements. D. The two atoms combine to create an

  33. 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

  34. Chemistry

    1. The delta Hf of an element in its standard state is defined to be a) 0 kJ/mol b) 10 kJ/mol c) -10 kJ/mol d) greater than 0 kJ/mol e) a unique value for each element I am assuming its a? 2. Which of the following statements are true? I) The reaction

  35. AP Chem

    Which of the following conditions would most likely affect the rate of a chemical reaction? A. Increasing the number of reaction steps B. Decreasing the size of the reaction vessel C. Increasing the concentration of reactants D. Decreasing the amount of

  36. 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

  37. Science

    1. what is a single replacement reaction A. A reaction in which two or more substances react to form a single substance*** B. A reaction in which one element takes place the place of another element in a compound. C. A reaction in which a compound breaks

  38. 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

  39. chemistry

    Which statement describes a chemical reaction at equilibrium? A. The forward reaction happens slightly faster than the reverse reaction. B. The reaction has stopped because all reactants have been used up. C. The forward reaction happens at the same rate

  40. chemistry

    How much heat is gained in joules by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 12 C

  41. 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

  42. 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

  43. 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?

  44. chemistry

    the product of a chemical reaction is phosphoric acid (h3po4). which elements must be in the reactants and how many atoms of each

  45. 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

  46. Chemistry

    If the equilibrium constant for a particular chemical reaction is 1 x 10^-3, what does this tell us? A. At equilibrium, there are more products than reactants. B. At equilibrium, there are more reactants than products. C. At equilibrium, there are 1 x

  47. Chemistry

    Which statement describes a chemical reaction at equilibrium? Reactant molecules and product molecules have the same velocity. Molecules of reactants and products collide with the same frequency. The concentrations of reactants and products are equimolar.

  48. 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

  49. science

    which of these describes a chemical reaction? a. Atoms are created by elements b. Atoms combine to form elements c. Atoms of two or more elements repel each other d. Atoms of two or more elements bond to each other** I’m not sure but i think it’s D

  50. Biology

    Which of the following would differ if you compared the sam reaction taking place with and without an enzyme? a. the chemical energy of the reactants**** b. the chemical energy of the products c. the energy required to start the reaction d. the overall

  51. 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

  52. thermochemistry

    A chemical reaction takes place in a container of cross-sectional area 100 cm2 . As a result of the reaction, a piston is pushed out through 19 cm against an external pressure of 596 torr. What is the value for w for this reaction?

  53. Science

    How Is a compound different from a mixture? it is made of one substance It cannot be made of organic materials It cannot be broken down It cannot be separated by a physical change I don't know This formula shows the chemical reaction that occurs when the

  54. 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

  55. SCIENCE 1

    Which of the following is a true statement about chemical equilibria in general A.there is only one set of equilibrium concentrations that equal the Kc value B.eqauilibrium is the result of cessation of all chemical change C.at equilibrium the rate of the

  56. Chem

    Chalcocite is an ore from which copper can be extracted for commercial use. The formula for this important ore is Cu2S. In the laboratory it is formed by the following reaction: 2Cu + S → Cu2S The reaction takes place in laboratory conditions that allow

  57. science

    1. which of the following is true about phtosynthesis? a. it is an exothermic reaction b. it is an endothermic reaction c. it produces carbon dioxide* d. it occurs in animals 2. atomic theory is a. subject to change if new information is discovered b. a

  58. Chem

    Which of the following are true regarding balancing chemical equations? A It takes practice in the form of trial and error to balance chemical equations B The law of conservation of matter should be applied by counting the number of atoms of every element

  59. Chemistry

    Activation energy is the heat released in a reaction the energy barrier between reactants and products the energy given off when reactants collide*** generally very high for a reaction that takes place rapidly

  60. chemisrty

    I have no idea how to do this activity..can someone please help!? In this activity you will investigate how chemical reactions are limited by the amount of reactants present. You will be using paper clips to represent atoms. You can describe the quantities

  61. Science (Chemistry)

    A chemical system within a sealed 1 L reaction vessel is described by the following reversible reaction equation: 2H2S(g) 2H(g) + S2(g) If the equilibrium constant is 0.000 004 200 at 1103 K find: (a) the reaction quotient intially (b) the order of

  62. Science

    What is a synthesis reaction? a reaction that occurs when one element within a compound is exchanged with another element a reaction that occurs when a single substance breaks apart and forms two or more new substances a reaction that occurs when a

  63. Chemistry

    A chemical reaction takes place in a container of cross-sectional area 100 cm2. As a result of the reaction, a piston is pushed out through 19 cm against an external pressure of 630 torr. What is the value for w for this reaction? (Sign does matter.)

  64. Chem

    3. Chalcocite is an ore from which copper can be extracted for commercial use. The formula for this important ore is Cu2S. In the laboratory it is formed by the following reaction: 2Cu + S ¨ Cu2S The reaction takes place in laboratory conditions that

  65. Chemistry

    Based on the chemical reaction: N2(g) + 3H2(g) → 2NH3(g), which statement is TRUE regarding the mass of the reactants compared to the mass of the products? a) There is not enough information given to answer this question. b) The mass of the reactants is

  66. Chemistry.

    Predict these reaction products. If a reaction takes place, balance the reaction if needed. If no reaction takes place then write no reaction. Cu+FeCl3--->CuCl3 + Fe Double replacement Al+HBr----> AgNO3 + KCL--->AgClKnO3 Double replacement

  67. science

    A scientist is studying a chemical reaction. She predicts that after the reaction the product will have less chemical potential energy than the reactants had originally. The scientist observes the reaction, and notes that no light or sound is produced.

  68. Chemistry

    Atom-Particle that cannont be divided in half becasue it is in its smallest form. Reactants-Substances that exist before the reaction begins. Endothermic Reaction-take in, or absorb heat energy. Exothermic Reaction- Release Heat energy Inhibitor-makes a

  69. Chemistry

    Use each equation to predict whether the relative entropy change is S(products) > S(reactants) or S(products) < S(reactants) and whether ΔS > 0 or ΔS < 0 for the chemical reaction represented. Justify your answer in each case. a.

  70. Science

    How is the law of conservation of mass used to balance a chemical equation? In a chemical equation, the products formed have the same atoms as the original reactants; however, the atoms may be rearranged. The law of conservation of mass states that the

  71. Chemistry

    When a mixture of 10.0 g of acetylene and 10.0 g of oxygen is ignited, a complete combustion of the reactants takes place. What is the limiting reagent of this reaction? How many grams of each of the reactants and products are present at the end of the

  72. Chemistry

    Activation energy is____ the heat released in a reaction*** the energy barrier between reactants and products the energy given off when reactants collide generally very high for a reaction that takes place rapidly

  73. 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

  74. Science

    How do the products and reactants of a chemical change compare? The mass of the products is greater than the mass of the reactants because energy is absorbed by the reaction. The mass of the products equals the mass of the reactants because energy is not

  75. Chemistry

    Before a chemical reaction reaches equilibrium, A. the reaction rates of the reactants and products increase. B. the reaction rate of the reactants increases and the reaction rate of the products decreases. C. the reaction rates of the reactants and

  76. Chemistry

    Potassium is a reactive element. Bromine is a reactive element. Write the complete balanced chemical equation using appropriate chemical symbols for the reaction when potassium reacts with bromine to make a solid product showing correct symbols and states

  77. AP Chemistry

    Choose a chemical reaction involving two or more reactants. For this reaction, how do you determine which reactant or reactants are limiting? Explain.

  78. Chemistry

    Please help me on this for my Midterm Review thank you very much... 1.For the reaction 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases? A. Shift to the right B. Shift to the left C. Doubles D. Does nothing E.

  79. Math

    Can anyone use these two questions as an example,I will do the rest,thank you! 1) y=x^2-3x, for -2≤x≤5. (Scales 2cm for x, 1cm for y) Find: a) gradient of the tangent to the curve at x=3. b) gradient of the tangent to the curve at x= -1. c) value of x

  80. Chemistry

    True or false 1. The energy of a collision between atoms or molecules must be greater than the activation energy for bonds to be broken? 2. Decreasing the temperature decreases the kinetic energy of the reactant, and the reaction goes more slowly? 3. two

  81. Chemistry

    when heated, sulfuric acid will decompose into sulfur trioxide and water. Write a chemical equation, using words, to represent this chemical reaction. Identify reactants and products. (I'm having trouble identifying the reactants and products & writing the

  82. Life Science

    I tried looking and can't find or understand where the following answer are. Please help me, I feel like I'm going crazy. I’m not sure about the answers I wrote but if someone could correct them and help me out with the ones I didn’t get.

  83. 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

  84. 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

  85. 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

  86. Chemistry

    Which of the following does NOT take place in a chemical reaction? a-new substances are formed b-neutrons are released c-energy is released or absorbed d-reactants disappear

  87. Chemistry

    Reaction Mechanism Formation of hydrogen bromide takes place as: H2 + Br 2 If the chemical reaction has occured by a mechanism that involves more than one step. What is the reaction occurs by the given mechanism?

  88. chem

    Why do we use excess reactants in a chemical reaction? Why are percent yields usually less than 100%? Is it because we want to maximize the amount of products produced, and reactions usually end up in a loss of reactants to the air, etc?

  89. science

    Hello! I need help with some Science things. 1. Where is a good place to find a picture that describes radioactive decay, fussion and fission/ 4. Scientists use the amount of radioactive isotopes found in rocks and fossils to calculate their ages. This

  90. Chemistry

    Which of the following statements is a false statement concerning characteristics of chemical equilibrium? a. Equilibrium is dynamic. b. For a specific reaction at a specific temperature, the equilibrium state will be dependent of the direction of approach

  91. 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

  92. Science

    What is the oxidation state of an element? the total number of protons an atom can gain or lose during a chemical reaction the total number of electrons an atom loses or gains during a chemical reaction the number of elements oxygen can bond with to form a

  93. chemistry

    Whatis the chemical name of the substance formed in the slow reaction that takes place when iron filings are mixed with water?

  94. AP Chemistry

    Hey guys! I'm stuck on some study guide problems... (On the bottom of this, I put what answers make sense to me) A) A factor that affects the speed of heterogeneous reactions but not of homogeneous reactions is 1)nature of reactants 2)concentration of

  95. chemistry

    How much heat is gained (in Joules) by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 14 C?

  96. chemistry

    How much heat is gained (in Joules) by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 10 C?

  97. chemistry

    1.equillibrium constant only changes for change in temp? not for change in pressure etc. 2. rate of reaction can be measure by measuring how long it takes for products to form or how long it takes for reactants to be consumed? so is the rate of consumption

  98. chemistry

    How much heat (in Joules) is gained by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 15C?

  99. chem.

    How much heat (in Joules) is gained by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 12C?

  100. college chem

    How much heat (in Joules) is gained by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 15C?

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