Chemistry Unit 2

Front

Is burning wood a chemical or physical change?

Back

Chemical change: A process where substances combine or break apart to form new substances.

Front

What is the process that turns a liquid into a gas?

Back

Evaporation: The process where liquid molecules gain enough energy to enter the gas phase.

Front

2H₂ + O₂ ----> ? What is the product?

Back

2H₂O: Water is produced when hydrogen and oxygen react.

Front

When a substance changes from one state of matter to another, what is this called?

Back

Phase Change: The transition of a substance from one state (solid, liquid, gas) to another.

Front

A substance made up of repeating patterns of molecule subunits is called?

Back

Extended structure: A material with a long-range order in its molecular arrangement.

Front

What is a chemical reaction?

Back

A process that leads to the transformation of one set of chemical substances to another.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed; it is conserved.

Front

What is an element?

Back

A pure substance that cannot be broken down into simpler substances by chemical means.

Front

What is a compound?

Back

A substance formed when two or more elements are chemically bonded together.

Front

What is the difference between a physical change and a chemical change?

Back

Physical change: A change that affects one or more physical properties of a substance without altering its chemical composition.