PreTest Atomic Structure

Front

What is the nucleus of an atom?

Back

The nucleus is a tiny but very dense, positively charged portion of the atom that holds most of the atomic mass.

Front

Which subatomic particle determines the name of the element?

Back

The proton determines the name of the element.

Front

What makes an isotope radioactive?

Back

An unstable combination of protons and neutrons in the nucleus makes an isotope radioactive.

Front

What is the mass number of an atom?

Back

The mass number is the sum of the protons and neutrons in the nucleus of that atom.

Front

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

Back

Number of neutrons = Mass Number - Atomic Number.

Front

What is an electron?

Back

An electron is a negatively charged subatomic particle that orbits the nucleus of an atom.

Front

What is an atomic number?

Back

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

Front

What is a neutron?

Back

A neutron is a neutral subatomic particle found in the nucleus of an atom.

Front

What is an isotope?

Back

An isotope is a variant of an element that has the same number of protons but a different number of neutrons.

Front

What is the difference between mass number and atomic number?

Back

Mass number is the total number of protons and neutrons, while atomic number is the number of protons only.