Atoms, Isotopes, Ions

Front

What is an isotope?

Back

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

Front

How do you calculate the mass number of an atom?

Back

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

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 also equals the number of electrons in a neutral atom.

Front

What happens when an atom gains or loses electrons?

Back

When an atom gains electrons, it becomes a negatively charged ion (anion). When it loses electrons, it becomes a positively charged ion (cation).

Front

What is the charge of a neutron?

Back

A neutron has no charge; it is neutral.

Front

How many protons are in a neutral atom of oxygen?

Back

A neutral atom of oxygen has 8 protons.

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

What is the mass number of bromine (Br) with 45 neutrons?

Back

The mass number of bromine with 45 neutrons is 80 (35 protons + 45 neutrons).

Front

What defines an ion?

Back

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Front

What is the difference between an atom and an ion?

Back

An atom is neutral, while an ion has a positive or negative charge due to the imbalance of protons and electrons.