8.6E Conservation of Mass Photosynthesis

The law of conservation of mass states________

• Matter can be created but not destroyed

• Matter can be destroyed but not created

• Mass is created during chemical reactions

• Mass is cannot be created nor destroyed

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

In a chemical reaction, the mass of the products

• Is greater than the reactants

• Is less than the reactants

• Equals the mass of the reactants

• Is always unpredictable

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which best explains why mass is conserved?

• Atoms are destroyed

• Atoms rearrange but are not lost

• Energy changes into matter

• Molecules disappear

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NGSS.MS-PS1-5

A reaction starts with 20 g of hydrogen and 80 g of oxygen. --> The product must weigh—

• 50 g

• 100 g

• 60 g

• 80 g

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

A student burns 10 g of paper. The ash weighs 2 g. Where is the missing mass?

• It disappeared

• It turned into water

• It became gases released into the air

• It was destroyed

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

Why must chemical equations be balanced?

• To show the products formed

• To follow the law of conservation of mass

• To make the math easier

• To prove new atoms are created

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NGSS.MS-PS1-5

Which chemical equation is balanced?

• H₂ + O₂ → H₂O

• 2H₂ + O₂ → 2H₂O

• H₂ + 2O₂ → H₂O

• H + O → H₂O

Tags

NGSS.MS-PS1-5

In the reaction

C + O₂ → CO₂

the number of oxygen atoms—

• Increases

• Decreases

• Stays the same

• Disappears

Tags

NGSS.MS-PS1-5

What happens to atoms in a chemical reaction?

• They rearrange to form new substances

• They are destroyed

• They vanish

• They multiply

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which is evidence that a chemical equation obeys conservation of mass?

• Same number of atoms on both sides

• More atoms in the products

Tags

NGSS.MS-PS1-5