Review for Unit 3 Test (Atoms and Elements)

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons.

Front

What are the three main subatomic particles of an atom?

Back

The three main subatomic particles are protons (positively charged), neutrons (neutral), and electrons (negatively charged).

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 do you calculate the total number of atoms in a chemical formula?

Back

To calculate the total number of atoms in a chemical formula, add the subscripts of each element in the formula.

Front

What is the mass number of an atom?

Back

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

Front

How do you find the number of neutrons in an atom?

Back

To find the number of neutrons, subtract the atomic number (number of protons) from the mass number.

Front

What is the significance of the number of electrons in an atom?

Back

The number of electrons determines the atom's charge and its chemical behavior. In a neutral atom, the number of electrons equals the number of protons.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Front

What is the formula for sulfuric acid?

Back

The formula for sulfuric acid is H2SO4.

Front

How many total atoms are in one molecule of H2O2?

Back

There are 4 total atoms in one molecule of H2O2 (2 hydrogen and 2 oxygen).