Atoms, Molecules, and Compounds

Question 1

Atom

Answer 1

The smallest particle of an element that can exist.

Question 2

Element

Answer 2

A pure chemical substance that cannot be physically split into a more simple substance. Each is made of one type of atom. Carbon, mercury, and hydrogen are examples.

Question 3

Molecule

Answer 3

The smallest particle of a substance that can exist. It is composed of two or more atoms.

Question 4

Compound

Answer 4

A substance made of atoms from two or more elements.

Question 5

Proton

Answer 5

A particle of matter that has a positive electrical charge and forms part of the nucleus of an atom.

Question 6

Neutron

Answer 6

A particle of matter that has no electrical charge and forms part of the nucleus of an atom.

Question 7

Electron

Answer 7

A particle of matter that has a negative electrical charge and travels around the nucleus of an atom.

Question 8

Atomic Number

Answer 8

Number of protons. Top number in the element box.

Question 9

Mass Number

Answer 9

Number of protons plus Neutrons. Bottom number in the element box.

Question 10

Chemical Symbol

Answer 10

A one or two letter representation of an element.

Question 11

Subscript

Answer 11

Tiny number to the right of the element symbol. Tells you how many atoms of that element.