8th_Topic 1_Lesson 1

Front

What must an atom have to be considered neutral if it has 12 positively charged subatomic particles?

Back

12 electrons.

Front

If oxygen-16 has 8 protons, how many neutrons does it have?

Back

8 neutrons.

Front

What is the charge of a neutron?

Back

No charge.

Front

What did the Rutherford gold foil experiment prove about atomic structure?

Back

It proved the positive charge is concentrated in a relatively small region of the atom.

Front

Who proposed that electrons move in definite orbits around the nucleus?

Back

Bohr.

Front

What are the three main subatomic particles in an atom?

Back

Protons, neutrons, and electrons.

Front

What is the charge of a proton?

Back

+1.

Front

What is the charge of an electron?

Back

-1.

Front

What is the atomic number of an element?

Back

The number of protons in the nucleus of an atom.

Front

What is the mass number of an atom?

Back

The total number of protons and neutrons in the nucleus.