Atom Basics

What is the center of an atom called?

• Electron cloud

• Nucleus

• Proton

• Neutron

Which subatomic particle is negatively charged?

• Proton

• Neutron

• Electron

• Quark

What is the atomic number of an element?

• The number of protons in the nucleus

• The number of neutrons in the nucleus

• The total number of protons and neutrons in the nucleus

• The total number of protons and electrons in the atom

What does the atomic mass of an element represent?

• The number of protons in the nucleus

• The number of electrons in the atom

• The total number of protons and neutrons in the nucleus

• The total mass of the electrons in the atom

Atoms of the same element with different numbers of neutrons are called:

• Isobars

• Isotopes

• Isomers

• Isoelectronic

Which subatomic particle contributes most to the mass of an atom?

• Electron

• Proton

• Neutron

• Both B and C are correct

What is the charge of a neutron?

• Positive

• Negative

• Neutral

• Variable

How is the electron cloud around the nucleus best described?

• A dense pack of electrons

• A precise orbit in which electrons move

• A region where electrons are likely to be found

• Empty space with no electrons

What determines the chemical properties of an atom?

• The number of neutrons

• The number of protons

• The number of electrons

• Both B and C are correct

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

An isotope of carbon has 6 protons and 8 neutrons. What is its atomic mass?

• 6

• 8

• 14

• 12