Atomic Number and Mass Number

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 is the mass number of an atom calculated?

Back

The mass number is calculated by adding the number of protons and neutrons in the nucleus.

Front

What is the relationship between atomic number and protons?

Back

The atomic number is equal to the number of protons in an atom.

Front

What do all atoms of the same element have in common?

Back

All atoms of the same element have the same number of protons.

Front

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

Back

The atomic number is 12.

Front

What is the mass number of a fluorine atom with 9 protons and 10 neutrons?

Back

The mass number is 19 (9 protons + 10 neutrons).

Front

How many neutrons are in a sodium atom with a mass number of 23?

Back

There are 12 neutrons (23 mass number - 11 protons).

Front

What is the atomic mass of an atom?

Back

The atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu).

Front

What is the difference between atomic number and mass number?

Back

The atomic number is the number of protons, while the mass number is the total number of protons and neutrons.

Front

What is an isotope?

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.