Periodicity

Question 1

Periodicity definition

Answer 1

The repeating pattern of physical and chemical properties going across the periods

Question 2

Classification of elements

Answer 2

s, p, and d blocked according to which orbitals the highest energy electrons are in

Question 3

atomic radius definition

Answer 3

distance from nucleus to outer electron

Question 4

Atomic radius across period

Answer 4

• decreases
• outer electrons in same shell
• same amount of shielding so stronger attraction between nucleus + outer shell electrons
• so outer shell electrons pulled closer to nucleus

Question 5

Atomic radius down a group

Answer 5

• increases
• more shells
• greater distance between nucleus and outer shell electron
• increased shielding amount so weaker attraction between nucleus and outer shell electrons
• so outer shell electrons further away

Question 6

Electronegativity definition

Answer 6

Ability of an atom to attract a pair of electrons in a covalent bond

Question 7

What is the most electronegative element?

Answer 7

Fluorine

Question 8

Electronegativity across a period

Answer 8

• increases
• more protons
• smaller atomic radius So stronger attraction between nucleus + 2 electrons in a covalent bond

Question 9

Electronegativity down a group

Answer 9

• decreases
• more shells/ shielding
• larger atomic radius So weaker attraction between nucleus + 2 electrons in covalent bonds

Question 10

Element bonding types

Answer 10

Na - metallic 
Mg - metallic
Al - metallic
Si - giant covalent
P4 - simple molecular
S8 - simple molecular
Cl2 - simple molecular 
Ar - monatomic

Question 11

Metallic bonding

Answer 11

• strong attraction between metal ions and delocalised electrons
• higher charge
• more delocalised electrons
• smaller ions with greater positive charge making bonding stronger
• higher energy to break bonds

Question 12

Macromolecular bonding

Answer 12

• many strong covalent bonds between atoms

- high energy needed to break covalent bonds

Question 13

Simple molecular bonds

Answer 13

• weak van der Waals forces between molecules

- little energy needed to break them

Question 14

Monotomic bonding

Answer 14

• weak van der Waals forces between atoms

Question 15

Giant covalent bonding

Answer 15

• many strong covalent bonds to break

Question 16

1st ionisation energy definition

Answer 16

Energy required to remember one mole of electrons from one mole of atoms in a gaseous state

Question 17

Ionisation energy trend down a group

Answer 17

• decreases
• more shells/ shielding
• greater distance between nucleus + outer electron
• so weaker attraction between nucleus + outer shell electrons
• less energy required to move one electron from outer shell

Question 18

Ionisation energy general trend across a period

Answer 18

• generally increases
• more protons/ greater nuclear charge
• same shell/ shielding
• atoms get smaller
• so stronger attraction from nucleus to electron in outer shell

Question 19

Ionisation energy group 2-3

Answer 19

• decreases
• electrons lost from -
  g2 : S orbital
  g3 : P orbital
• p orbital is higher energy than a orbital, so easier to lose electron

Question 20

Ionisation energy group 5-6

Answer 20

• decreases
• g5 element - loses electron from orbital with one electron (p3)
• g6 element - loses electron from orbital with 2 electrons (p4)
• when second election is added to orbital there is a slight repulsion between the two negatively charged electrons which makes the second electron easier to remove

Question 21

How are elements in the periodic table ordered?

Answer 21

• in s, p + d blocks according to which orbitals the highest energy electrons are in