Atom Basics

What is the smallest unit of matter?

• Cells

• Atoms

• Molecules

• Planets

What is the central part of an atom called?

• center

• nucleus

• heart

• core

Which subatomic particle has a positive charge?

• Proton

• Electron

• Photon

• Neutron

What is the charge of an electron?

• 0 C

• -1.6 x 10^-19 C

• -1.2 x 10^-19 C

• 2.4 x 10^-19 C

What is the charge of a proton?

• Zero

• Neutral

• Positive

• Negative

What is the charge of a neutron?

• Positive

• Neutral

• Charged

• Negative

Changing the number of neutrons of an atom changes its:

• isotope

• element

• ion

• charge

What is the atomic number of an element?

• The atomic number of an element is the number of protons in its nucleus.

• The atomic number of an element is the number of neutrons in its nucleus.

• The atomic number of an element is the number of electrons in its nucleus.

• The atomic number of an element is the number of isotopes it has.

What is the mass number of an element?

• Total number of isotopes

• Total number of electrons

• Total number of protons + total number of neutrons

• Total number of protons

What is an isotope?

• Isotopes are not related to atoms

• Atoms with different numbers of electrons

• Atoms of the same element with different numbers of neutrons.

• Different types of atoms within the same element