Atoms

Question 1

Matter

Answer 1

Any substance that occupies space and has mass

Question 2

Elements

Answer 2

Unique forms of matter with specific chemical and physical properties that cannot break down into smaller substances by ordinary chemical reactions.

Question 3

Atom

Answer 3

The smallest unit of matter that retains all of the element’s chemical properties.

Question 4

Nucleus

Answer 4

The atom’s center, containing protons and neutrons

Question 5

Proton

Answer 5

a stable, subatomic particle that is positively charged. The atom’s number of protons make up its atomic number

Question 6

Neutron

Answer 6

a subatomic particle that contains no electric charge, but contains mass. One neutron is approximately the same mass as one proton.

Question 7

Electrons

Answer 7

They weight 1/1800th of the mass of a proton. They orbit around the nucleus and contain a negative charge

Question 8

Atomic number

Answer 8

An element’s total number of protons

Question 9

Mass Number

Answer 9

An element’s total number of protons plus neutrons

Question 10

Atomic mass

Answer 10

The average mass number of all the element’s naturally occurring isotopes.

Question 11

Isotopes

Answer 11

Different forms of an element that have the same number of protons but a different number of neutrons.

Question 12

radioisotopes

Answer 12

Isotopes that emit neutrons, protons, and electrons, and attain a more stable atomic configuration (lower level of potential energy)

Question 13

Periodic Table

Answer 13

An organizational structure that contains all the known elements

Question 14

Chemical reactivity

Answer 14

An element’s ability to combine and to chemically bond with each other.

Question 15

Molecule

Answer 15

Two or more atoms that are chemically bonded to each other

Question 16

Orbitals

Answer 16

The way electrons are organized; they are shells outside of the nucleus that hold electrons and are organized from most stable to least

Question 17

Octet rule

Answer 17

With the exception of the innermost shell, atoms are more stable energetically when they have eight electrons in their valence shell, or outermost electron shell. Atoms are organized with up to two electrons in their first shell, followed by 8 in each until you hit the valence shell.

Question 18

Valence shell

Answer 18

The outermost shell of electrons in an element