8th Grade Science Semester Exam Review

Front

What is the composition of potassium sulfate (K₂SO₄)?

Back

2 atoms of potassium, 1 atom of sulfur, and 4 atoms of oxygen.

Front

What is an example of unsafe laboratory practice?

Back

Mixing chemicals before reading instructions.

Front

How should students safely dispose of chemicals after an experiment?

Back

By following directions from the teacher for each chemical.

Front

What best describes iron (Fe) in a chemical reaction?

Back

Element.

Front

Which element is in the same group as sodium (Na)?

Back

Potassium (K).

Front

What is a molecule?

Back

A group of two or more atoms bonded together.

Front

Define a chemical compound.

Back

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

Front

What is the purpose of wearing safety goggles in a lab?

Back

To protect eyes from harmful chemicals and debris.

Front

What is the difference between an element and a compound?

Back

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

Front

What is the chemical formula for water?

Back

H₂O.