Rearranging Atoms

Which of the models of a chemical reaction best represents the Law of Conservation of Mass?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-5

Which is true during a chemical reaction?

• Some of the atoms are destroyed, and some of the atoms rearrange to form a different substance or different substances.

• All of the atoms that make up the reactants rearrange to form the products.

• All of the atoms are destroyed.

• Some of the atoms rearrange to form new substances and the others change into different atoms.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which of the following best describes a chemical reaction?

• Atoms are rearranged to form new substances.

• Atoms are destroyed and new ones are created.

• Atoms remain unchanged and only energy is transferred.

• Atoms are rearranged but no new substances are formed.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

In the reaction @@ ext{2H}_2 + ext{O}_2 ightarrow ext{2H}_2 ext{O}@@, what happens to the atoms?

• They are rearranged to form water molecules.

• They are destroyed and new water molecules are created.

• They remain as hydrogen and oxygen atoms.

• They change into different elements.

Tags

NGSS.MS-PS1-5

What is conserved in a chemical reaction?

• Mass and energy

• Only mass

• Only energy

• Neither mass nor energy

Tags

NGSS.MS-PS1-5

Which of the following is an example of a physical change rather than a chemical change?

• Melting ice

• Burning wood

• Rusting iron

• Baking a cake

Tags

NGSS.MS-PS1-4

What is the role of a catalyst in a chemical reaction?

• It speeds up the reaction without being consumed.

• It is consumed in the reaction to form products.

• It slows down the reaction.

• It changes the products of the reaction.

Tags

NGSS.HS-PS1-5

Which of the following statements is true about chemical bonds during a reaction?

• Chemical bonds are broken and new bonds are formed.

• Chemical bonds remain unchanged.

• Chemical bonds are only broken, not formed.

• Chemical bonds are only formed, not broken.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

In a balanced chemical equation, what do the coefficients represent?

• The number of molecules or moles of each substance.

• The mass of each substance.

• The volume of each substance.

• The energy change of the reaction.

Tags

NGSS.MS-PS1-5

What is the main difference between a chemical and a physical change?

• Chemical changes result in new substances; physical changes do not.

• Physical changes result in new substances; chemical changes do not.

• Both result in new substances.

• Neither result in new substances.

Tags

NGSS.MS-PS1-2