Chemical Equation Review

The Law of Conservation of Matter says that during a chemical reaction...

• matter can be created but not destroyed

• matter cannot be created or destroyed

• the mass of the products will be less than the reactants

• you can conserve energy by turning out the lights

Tags

NGSS.MS-PS1-5

After we made the circuit boards, we measured the concentration of the copper chloride. What does concentration mean?

• the amount of one substance mixed with another substance

• focusing to solve a problem in science

• parts per million

• burning something

Which units did we use to measure concentration?

• drops

• kilograms

• parts per million

• grams per milliLiter

When atoms rearrange to form a new molecule, we call it a ....

• solution

• chemical reaction

• physical change

• concentration

Tags

NGSS.MS-PS1-5

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Which of the following are signs that a chemical reaction occurs?

• color change

• forming a gas/bubbles

• temperature change

• all are correct

Tags

NGSS.MS-PS1-2

In the equation below, which are the reactants?

• NaCl

• Na and NaCl

• Na and Cl₂

• Na, Cl₂, and NaCl

Tags

NGSS.MS-PS1-5

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Is this equation balanced?

• yes

• no

Tags

NGSS.MS-PS1-5

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In this equation, what are the products?

• NH₃

• N₂ + H₂

• Nitrogen and Hydrogen

• N₂, H₂, and NH₃

Tags

NGSS.MS-PS1-5

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When I demonstrated making a ciruit board, I used a process called etching to wear away the extra copper. Is this a chemical change or physical change? Choose the answer that best explains why.

• physical change because the copper was the same before and after

• physical change because we changed the shape of the copper but not the molecule

• chemical change because the copper changed to a different molecule

• chemical change because there was an explosion

Tags

NGSS.MS-PS1-2

Why do we balance equations?

• because we need to change the type of elements

• because we need to begin and end a reaction with the same number of each atom

• because the equation was not written down correctly the first time

• because we need to reactants to be heavier than the products

Tags

NGSS.MS-PS1-5