Chemistry 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 melting, freezing, and sharpening a pencil.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include rusting, burning, and baking.

Front

Where are electrons located in an atom?

Back

Electrons are located outside the nucleus of an atom.

Front

What is the chemical formula for water?

Back

The chemical formula for water is H2O, which consists of 2 hydrogen atoms and 1 oxygen atom.

Front

How do you calculate density?

Back

Density is calculated using the formula: Density = Mass/Volume.

Front

What is the density of aluminum if its mass is 6 g and volume is 2.22 cm³?

Back

The density of aluminum is 2.7 g/cm³.

Front

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

Back

A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element.

Front

What are the three main subatomic particles in an atom?

Back

The three main subatomic particles are protons, neutrons, and electrons.

Front

What charge do protons have?

Back

Protons have a positive charge.