9th Grade Physical Science Mid-Term

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

How many protons does an atom with an atomic number of 28 have?

Back

28

Front

What is the SI unit for mass?

Back

Kilogram (Kg)

Front

What does the law of conservation of mass state?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.

Front

What type of graph is used to show trends over time?

Back

Line graph

Front

What is a compound?

Back

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

Front

What is the difference between a mixture and a compound?

Back

A mixture is a combination of two or more substances that are not chemically combined, while a compound is a substance formed from two or more elements that are chemically bonded.

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.

Front

What is the formula for calculating density?

Back

Density = Mass/Volume

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is made up of two or more elements chemically combined.