Units 1 & 2 Review

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include breaking a cracker or ripping paper.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and the rearrangement of atoms.

Front

How many atoms of Hydrogen are in H₂O?

Back

2

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include iron (Fe), oxygen (O), and gold (Au).

Front

What is a compound?

Back

A compound is a substance formed when two or more elements are chemically bonded together. An example is iron oxide (FeO).

Front

What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded. Mixtures can be homogeneous or heterogeneous.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture in which the composition is uniform throughout. An example is saltwater.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture in which the composition is not uniform throughout. An example is a salad.

Front

What happens to iron when it rusts?

Back

When iron rusts, it reacts with oxygen in the presence of moisture to form iron oxide (FeO), which is a compound.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.