The Structure of the Atom – Module 3 Test

Front

What is the definition of an isotope?

Back

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

Front

Back

In the nuclear symbol, A is the mass number (protons + neutrons), Z is the atomic number (number of protons), and X is the chemical symbol of the element.

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).

Front

What is the charge of an electron?

Back

An electron has a negative charge.

Front

What is the main conclusion of Rutherford's gold foil experiment?

Back

The atom is mostly empty space with a small, dense, positively charged nucleus.

Front

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

Back

Subtract the atomic number (Z) from the mass number (A): Neutrons = A - Z.

Front

What subatomic particles are found in the nucleus of an atom?

Back

The nucleus contains protons and neutrons.

Front

What is the mass of an electron compared to protons and neutrons?

Back

The mass of an electron is much smaller than that of protons and neutrons.

Front

What is the significance of the atomic number?

Back

The atomic number determines the identity of an element and the number of protons in its nucleus.