Periodicity

Question 1

What does the Periodic Table arrange the known elements into?

Answer 1

Atomic (proton) number

Question 2

What do all the elements along a period have the same number of?

Answer 2

Electron shells

Question 3

What do all the elements down a group have the same number of?

Answer 3

Outer electrons

Question 4

What does the stepped line divide?

Answer 4

Metals and Non Metals

Question 5

What kind of properties do elements that touch the stepped line have? What are these elements known as?

Answer 5

Both metal and non metal properties. They are metalloids

Question 6

What block is groups 1 and 2 in, on the periodic table?

Answer 6

S block

Question 7

Why is group 1 and 2 in the s block?

Answer 7

All the elements have their highest energy electrons in the s-orbital

Question 8

What block is groups 3 to 0 in, on the periodic table?

Answer 8

P block

Question 9

Why is groups 3 to 0 in the p block?

Answer 9

The elements have their highest energy electrons in the p-orbital

Question 10

Elements that have their highest energy electrons in the d-orbital are in which block?

Answer 10

d block

Question 11

Why are the transition metals and d-block not exactly the same?

Answer 11

Scandium and Zinc aren’t transition metals as they don’t form compounds where they have partly filled d-orbitals

Question 12

What block are the radioactive elements in, on the periodic table?

Answer 12

f block

Question 13

Describe the reactivity of the s block elements

Answer 13

s block elements get more reactive going down the group

Question 14

Describe the reactivity of the non metals

Answer 14

They get more reactive going up the group

Question 15

Describe the reactivity of the d block elements

Answer 15

They are usually quite unreactive. This is where most useful elements are found

Question 16

Describe the reactivity of the lanthanides and what do they form?

Answer 16

The lanthanides are rarely met. They form 3+ ions and have similar reactivity

Question 17

Describe the reactivity of the actinides and what do they do?

Answer 17

Actinides are radioactive. They trace elements except for Thorium and Uranium

Question 18

Does atomic radius increase or decrease going a long a period?

Answer 18

Decreases

Question 19

Why does atomic radius decrease going along a period?

Answer 19

Due to an increased nuclear charge for the same number of electron shells.
The outer electrons are pulled closer to the nucleus as increased charge produces a greater attraction so decreases

Question 20

Does atomic radius increase or decreasing going down a group?

Answer 20

Increases

Question 21

Why does atomic radius increase going down a group?

Answer 21

With each increment down a group an electron shell is added each time.
This increases the distance between outer electrons and nucleus reducing power of attraction.
More shells increases shielding where the inner shells create a barrier that blocks forces.
Nuclear attraction reduced further, atomic radius increases

Question 22

Why do melting points vary across period 3?

Answer 22

As they depend on the structure and the bonding of the element

Question 23

What type of bonding do Na, Mg and Al have? Are these metals or non metals?

Answer 23

Na, Mg and Al are metals with metallic bonding

Question 24

Does the melting point of Na, Mg and Al increase or decrease?

Answer 24

Increase

Question 25

Why does the melting point of Na,Mg and Al increase going across period 3?

Answer 25

As their metallic bond gets stronger. This is due to increasing positive charge, increased delocalised electrons and decreasing atomic radii

Question 26

Describe the structure of silicone in period 3?

Answer 26

It is macromolecular and tetrahedral. Strong covalent bonds links its atoms

Question 27

Describe the melting point of silicone

Answer 27

A lot of energy is required to break the strong covalent bonds giving a high melting point

Question 28

Describe the melting points for Phosphorus (P4), Sulphur (S8), and Chlorine (Cl2)

Answer 28

They are molecular. Their melting point depends on Van der Waal forces which are weak and easily broken. More atoms in a molecule mean greater VDW forces so the boiling point S>P>Cl

Question 29

Describe the structure and bonding of Argon

Answer 29

Argon is monatomic so its VDW forces are very weak. Its a noble gas that exists as individual atoms with a full outer shell of electrons

Question 30

Describe the melting point of Argon

Answer 30

The full outer shell of electrons makes the atom very stable so the melting point of argon is very low and it exists as a gas at room temperature

Question 31

Across a period does ionisation energy increase or decrease? Why?

Answer 31

Increases because of the decreasing atomic radius and increasing nuclear charge means that the outer electrons are held more strongly and so more energy is required to remove the outer electron and ionise the atom

Question 32

Does ionisation energy increase or decrease going down a group? Why?

Answer 32

Decreases as the nuclear attraction between the nucleus and outer electrons reduces and increasing amounts of shielding means less energy is required to remove the outer electron