atomic number and mass number

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

What is the atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom.

Front

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

Back

Number of neutrons = Mass number - Atomic number.

Front

What is the relationship between protons and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

If an atom has 12 protons, what is its atomic number?

Back

The atomic number is 12.

Front

An atom of carbon has 6 protons and 6 neutrons. What is its mass number?

Back

The mass number is 12 (6 protons + 6 neutrons).

Front

What is the mass number of an atom with 5 protons and 6 neutrons?

Back

The mass number is 11 (5 protons + 6 neutrons).

Front

How many electrons does a neutral atom of sodium (Na) have?

Back

A neutral atom of sodium has 11 electrons.

Front

What is the mass number of an atom with 8 protons and 10 neutrons?

Back

The mass number is 18 (8 protons + 10 neutrons).

Front

If an element has an atomic number of 15, how many protons does it have?

Back

It has 15 protons.