Chemical reactions ____.

• occur only in living organisms

• create and destroy atoms

• only occur outside living organisms

• produce new substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Identify the letter of the choice that best completes the statement or answers the question. 2. Everyday equations describe ____.

• thermonuclear reactions

• everyday processes

• chemical reactions

• biological chemistry

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-5

What does the symbol Δ in a chemical equation mean?

• Heat is supplied to the reaction.

• A catalyst is needed.

• yields

• precipitate

Chemical equations ____.

• describe chemical reactions

• show how to write chemical formulas

• give directions for naming chemical compounds

• describe only biological changes

Tags

NGSS.HS-PS1-7

A skeleton equation does NOT show which of the following?

• the correct formulas of the reactants and products

• the reactants on the left, the products on the right

• an arrow connecting the reactants to the products

• the relative amounts of reactants and products

Which set is correct?

• (g), grams

• (l), liters

• (aq), dissolved in water

• (s), solid product

A catalyst is ____.

• the product of a combustion reaction

• not used up in a reaction

• one of the reactants in single-replacement reactions

• a solid product of a reaction

Which of the following is the correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide?

• P(s) + O2(g) → PO2(g)

• P(s) + O(g) → P3O5(g)

• P(s) + O2(g) → P2O5(s)

• P2O5(s) → P2(s) + O2(g)

When the equation Fe + Cl2 → FeCl3 is balanced, what is the coefficient for Cl2?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-7

Which of the following statements is NOT true about what happens in all chemical reactions?

• The ways in which atoms are joined together are changed.

• New atoms are formed as products.

• The starting substances are called reactants.

• The bonds of the reactants are broken and new bonds of the products are formed.

Tags

NGSS.HS-PS1-7