Law of Conservation of Mass Review

During a chemical reaction, the total amount of mass _____.

• increases.

• decreases.

• may increase or decrease.

• does not change.

Tags

NGSS.MS-PS1-5

How are photosynthesis and cellular respiration an example of the law of conservation of mass?

• Photosynthesis makes food.

• Cellular respiration makes energy.

• No atoms are lost or created in these reactions

Tags

NGSS.MS-LS1-6

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A chemical equation must _____.

• show energy.

• be balanced.

• use subscripts.

• use coefficients.

Tags

NGSS.MS-PS1-5

What does photosynthesis make for a plant?

• Energy

• Food

• Carbon dioxide

• Seeds

Tags

NGSS.MS-LS1-6

A student asks why the ashes from a fire have a much lower mass than the wood that was burned. Which is the correct answer to their question?

• Gases are released into the air

• Atoms in the wood are destroyed

• Heat causes molecules to lose density

• Water inside the wood solidifies

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following equations is balanced?

• 2 Al + 3 O₂ ⟶ 2 Al₂O₃

• 4 Al + 2 O₂ ⟶ 3 Al₂O₃

• Al + O₂ ⟶ Al₂O₃

• 4 Al + 3 O₂ ⟶ 2 Al₂O₃

Tags

NGSS.MS-PS1-5

How do most complex organisms get their energy?

• Through eating

• Through cellular respiration

• Through sleeping

• Through breathing

Tags

NGSS.MS-LS1-7

How many oxygen atoms are in this chemical formula? Fe₂O₃

• 6 oxygen atoms

• 2 oxygen atoms

• 3 oxygen atoms

• 4 oxygen atoms

Tags

NGSS.MS-PS1-1

How many Iron atoms are in this chemical formula? 2Fe₂O₃

• 4 Iron atoms

• 2 Iron atoms

• 3 Iron atoms

• 6 Iron atoms

Tags

NGSS.MS-PS1-1

Which equation best represents the law of conservation of mass? 

• A
• B
• C
• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5