Atomic Number, Mass Number and Isotopes

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

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 are isotopes?

Back

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

Front

How do you calculate the average atomic mass of an element with multiple isotopes?

Back

Average atomic mass = (mass of isotope 1 × abundance) + (mass of isotope 2 × abundance) + ...

Front

What is the relationship between atomic number and isotopes?

Back

All isotopes of an element have the same atomic number but different mass numbers.

Front

What subatomic particle has a positive charge?

Back

Proton.

Front

What subatomic particle has no charge?

Back

Neutron.

Front

What subatomic particle has a negative charge?

Back

Electron.

Front

If an element has an atomic number of 6, how many protons does it have?

Back

It has 6 protons.

Front

If an isotope of lithium has a mass number of 7, how many neutrons does it have?

Back

It has 4 neutrons (7 mass number - 3 protons = 4 neutrons).