Atomic Structure

Question 1

Define atom

Answer 1

Consists of 3 subatomic particles (protons, neutrons and electrons)

Question 2

Define molecule

Answer 2

Groups of atoms

Some are just one element and others are made up of more than one element

Question 3

Charges of the subatomic particles that make up a atom (general)

Answer 3

Proton:
Positive

Neutron:
Neutral

Electron:
Negative

Question 4

Specific relative mass and relative charge of subatomic particles that make up an atom

Answer 4

Proton:
Mass = 1
Charge = +1

Neutron:
Mass = 1
Charge = 0

Electron:
Mass = 0.0005
Charge = -1

Question 5

Describe nucleus

Answer 5

• middle of atom
• contains protons and neutrons
• positive charge because of protons
• compared to size of atom, nucleus is small

Question 6

Describe electrons

Answer 6

• move around the nucleus in shells
• negatively charged
• tiny, but orbitals cover a lot of space
• size of orbitals depends of atom size
• electrons have virtually no mass

Question 7

How to find the number of electrons

Answer 7

Equal to the number of protons

Question 8

Atomic number
Tells you….

Position next to element symbol on periodic table

Answer 8

Tells: how many protons there are

Position: bottom (Na = 11)

Question 9

Mass number
Tells you

Position next to element symbol on periodic table

Answer 9

Tells: total number of protons and neutrons in atom

Position: top

(Na = 23)

Question 10

Isotopes

Definition

Answer 10

Isotopes are different atomic forms of the same element, which have the same number of protons but different numbers of neutrons

Question 11

Relative atomic mass (Ar)

Answer 11

Average mass of all the isotopes of an element

How to find it:

• multiply the mass of each isotope by its relative abundance
• add both together
• divide by sum of relative abundances

Question 12

Relative abundance

Definition

Answer 12

How much there is of each isotope compared to the total amount of the element in the world