Credit Recovery Q's Master List

What is the law of conservation of mass?

• Energy can neither be created nor destroyed

• Matter can neither be created nor destroyed

• Kinetic energy of a substance is directly related to its temperature

• An SI unit used to measure the amount of any substance

How did Dalton describe the process of a chemical reaction?

• Chemical reactions involve the rearrangement of atoms

• Chemical reactions involve the breaking down of atoms

• Chemical reactions involve the melting of atoms

• Chemical reactions involve the relative size of atoms

Why don’t we change the subscripts in order to balance an equation?

• Changing the subscripts was not what Dalton initially proposed

• Changing the subscripts is sometimes okay under certain circumstances

• Changing the subscripts alters the ratio of atoms in a molecule

• Changing the subscripts is a quicker way to balance chemical equations

What are combination reactions?

• Two or more substances combine to form a single new substance

• A compound breaks down into two or more simpler substances

• One element replaces a similar element in a compound

• The positive and negative ions of two compounds exchange places to form two new compounds

Write the product of the following reaction: Mg + H₂O→

• O₂

• H₂

• H₃(MgO)₂

• Mg(OH)₂

Is CH₄ + 2O₂ → CO₂ + 2H₂O a combination reaction? Explain your answer.

• Yes, this is a combination reaction

• No, this is a combustion reaction

What is a decomposition reaction?

• Two or more substances combine to form a single new substance

• A compound breaks down into two or more simpler substances

• One element replaces a similar element in a compound

• The positive and negative ions of two compounds exchange places to form two new compounds

What is usually needed for a decomposition reaction to take place?

• Oxygen gas

• A catalyst

• An output of energy

• An input of energy

Are elements always the product of a decomposition reaction?

• Yes

• No

What is needed for a combustion reaction to take place?

• Oxygen gas

• A catalyst

• An output of energy

• An input of energy