Atoms

Question 1

Protons

Answer 1

Symbol: p / p+
Charge: 1+
Mass: 1amu
Location: nucleus

Question 2

Neutron

Answer 2

Symbol: n / n0
Charge: 0
Mass: 1amu
Location: nucleus

Question 3

Electron

Answer 3

Symbol: e-
Charge: 1-
Mass: 0.0005amu
Location: outside nucleus

Question 4

Structure of an Atom

Answer 4

Nucleus (p & n)

Large empty space around nucleus (shells containing e-)

Question 5

Nucleus

Answer 5

Contains the majority of the mass of an atom (p&n)

Small compared to the rest of the atom

Question 6

Atomic Number

Answer 6

Location: above the chemical symbol
Symbolizes: the # of p+ of that element
Always the same for every atom of that element.

Question 7

Mass Number

Answer 7

Location: nucleus
Symbolizes: n0 + p+ of an atom

Question 8

Nuclear Symbol

Answer 8

For an atom, gives the # of p+, n0, and e-

x -> Mass number
Y -> Chemical symbol
z -> Atomic number

Must note # of each subatomic particle.

Question 9

Isotopes

Answer 9

• Are atoms of the same element (same atomic number) but have a different mass number (ie. diff amount of n0).
• Occurs naturally in the world
• Must be comparable
• to find the # of n0 = mass # - atomic #

Question 10

Atomic Symbol

Answer 10

For an atom, gives the mass # and atomic #

x -> Mass # (p+n)
Y -> Chemical symbol
z -> Atomic # (p)

Question 11

Average Atomic Mass

Answer 11

Location: under the element on the PT
Symbol: amu
Symbolizes: the weighted average of the masses of all the naturally occurring isotopes of that element

Question 12

Energy Level

Answer 12

• orbits surrounding the nucleus
• can hold specific # of electrons on each orbit
• 1st orbit:2
• post-1 orbit: 8
• last orbit is called the ‘valence’ orbit

Question 13

Lewis Dot Symbol

Answer 13

Chemical symbol + valence electrons distributed on each of 4 sides (paired if there are 2 on a side)
-also called ‘Electron dot symbol’

Question 14

Valence Electrons

Answer 14

# of e- on the outermost orbit, or the 'valence' orbit.
Can be determined easily by noting the Group#

Question 15

Atomic Size

Answer 15

Describes the size of a single atom by using the atomic radius.
Increases going left and down the PT

Question 16

Atomic Radius

Answer 16

Determined by the distance of the ve- from the nucleus.

• Increases going down a Group due to increase in orbits (ergo more space/distance)
• Decreases going right across a Period due to increase in p+ which increases strength of attraction of e-, thus creating tighter orbits

Question 17

Ionization Energy

Answer 17

Energy required to remove a ve- from an atom in its gaseous state
-Decreases going left and down the PT as the distance of ve- from nucleus increases (atomic radius) since it’s easier to snatch a ve- when the attraction of the nucleus is weak

Question 18

Cation

Answer 18

A positively charged ion (missing e-)

“Ca + ion”

Question 19

Anion

Answer 19

A negatively charged ion (added e-)

“A negative ion”

Question 20

Octet Rule

Answer 20

8 ve-
Associated with the stability of noble gases (excluding He; stable @ 2ve-)
Atoms at their most stable w/8ve- by losing, gaining or sharing their ve-
Once achieved the atom does not react with other atoms

Question 21

Isoelectronic

Answer 21

‘iso’ - ‘same’, ‘electronic’ - refers # of e-

When an atom of an element has the equal number of e- as another atom of an element. Each atom seeks to become isoeletronic with its nearest noble gas.

Eg. Na1+ is isoelectronic to Ne (both have a total of 10e-)

Question 22

Compound

Answer 22

The result of a transfer/share of ve- between 2 atoms to form a compound stable electron configuration.

Attempt to reach octet or duet rule for each atom through ionic or covalent bonding.

Question 23

Molecule

Answer 23

• Union of 2+ atoms of the same element

- Also the smallest part of a compound that retains the properties of that compound