Unit 3 HMH Science (7th grade)

What is a system in the context of chemical reactions?

• A process that involves only physical changes

• A set of interacting parts that can be tiny or huge

• Only a chemical reaction between reactants and products

• A collection of chemical elements

Tags

NGSS.MS-PS1-5

What is the term for a substance being dissolved in a solution?

• Solvent

• Solution

• Reactant

• Solute

Which of the following is an example of a physical property?

• Flammability

• Reactivity

• Melting point

• Ability to rust

What does the law of conservation of matter state?

• Matter cannot be created or destroyed in a reaction

• Energy is never involved in chemical reactions

• Reactants are always greater than products

• Matter is destroyed in chemical reactions

Tags

NGSS.MS-PS1-5

What is a chemical reaction?

• A process where atoms are rearranged to form new substances

• The dissolution of solutes in a solvent

• A change in color or shape

• A reversible physical change

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which is a sign of a chemical reaction?

• Change in shape

• Gas production

• Increase in temperature without external heating

• A mixture forming

Tags

NGSS.MS-PS1-2

What is a subscript in a chemical formula used to show?

• The number of molecules in the formula

• The number of atoms of an element present

• The types of reactions involved

• The solvent used in the reaction

What is the difference between a reactant and a product in a chemical reaction?

• Reactants are substances formed, products are starting substances

• Reactants are starting substances, products are substances formed

• Reactants are created during a reaction, products are not

• There is no difference

Tags

NGSS.MS-PS1-1

What does the coefficient in a chemical equation indicate?

• The number of atoms in a molecule

• The number of molecules in a reaction

• The temperature of the reaction

• The type of bond formed

What is an example of a synthetic material?

• Wood

• Plastic

• Water

• Stone

Tags

NGSS.MS-PS1-3