Atomic Structure

Front

What is the atomic number of an atom?

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 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 smallest unit of matter that retains its properties?

Back

The smallest unit of matter is an atom.

Front

Who discovered protons in the nucleus?

Back

Ernest Rutherford discovered that the nucleus contains positively charged particles called protons.

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.

Front

What is the difference between atomic number and mass number?

Back

Atomic number is the number of protons, while mass number is the sum of protons and neutrons.

Front

What are isotopes?

Back

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

Front

What is the charge of a proton?

Back

A proton has a positive charge.

Front

What is the charge of a neutron?

Back

A neutron has no charge (it is neutral).