Chapter 7

Question 1

What are elements arranged by?

Answer 1

In order of increasing atomic (proton) number

Question 2

Where are the s-blocks?

Answer 2

Group 1 and 2.

Question 3

Where are the d-blocks?

Answer 3

Middle of elements.

Question 4

Where are the p-block elements?

Answer 4

On the right hand side of periodic table.

Question 5

What do elements in the same group have?

Answer 5

Have the same number of outer electron shells and similar chemical properties.

Question 6

What do elements in the same period have?

Answer 6

Have the same number of electron shells.

Question 7

What are rows in the periodic table called?

Answer 7

Periods.

Question 8

What are columns in the periodic table called?

Answer 8

Groups.

Question 9

What is periodicity mean?

Answer 9

Is the repeating trends in the physical and chemical properties of the elements along periods.

Question 10

What are the sub-shells in Period 2?

Answer 10

2s- 2p

Question 11

What are the sub-shells in Period 3?

Answer 11

3s - 3p - 3d

Question 12

What is first ionisation energy?

Answer 12

Is the energy required to remove one mole of electrons from one atoms in the gaseous state.

Question 13

General equation for first ionisation energy?

Answer 13

X(g) to X+(g) + e-

Question 14

What is successive ionisation energy?

Answer 14

Is the removal of more than 1 electron from the same atom.

Question 15

General equation for successive ionisation energies?

Answer 15

X(n)+(g) to X(n+1)+(g) + e-

Question 16

Why happens to first ionisation energies down a group? why?

Answer 16

It decreases down a group: the no. of shells increases, which increases atomic radius and shielding. Attraction between the nucleus and other electrons decreases despite an overall increase in nuclear charge.

Question 17

Why happens to first ionisation energies down a period? why?

Answer 17

It increases across a period. As the nuclear charge increases but with a similar amount of shielding. This means there is a decrease in atomic radius. Attraction between the nucleus and outer electrons increases.

Question 18

Why does Na have a lower first ionisation than Neon?

Answer 18

As Na will have the it’s outer electron in the 3s sub-shell which is further from the nucleus and more shielded, so Na’s outer electron is easier to remove + has a lower ionisation energy.

Question 19

Why is there a drop in ionisation energy between Mg and Al?

Answer 19

Because Al is starting to fill out a full 3P sub-shell, whereas Mg has it’s outer electron in the 3s sub-shell. The electron in the 3P subshell are slightly easier to remove because the 3P electrons are higher in energy and slightly shielded by the 3s electrons.

Question 20

Why is there a drop in ionisation energy between P and S?

Answer 20

In sulfur, the 4 electrons in the 3p level, are all paired. While in phosphorus there are 2 paired electrons and 1 lone electron in the 3p level. Due to the electron repulsion of the paired electrons in sulfur, less energy is required to remove 1 mole of electrons from its sub-level, as there is less of an attraction of these electrons towards its nucleus. Therefore, the first ionisation energy for sulfur will be slightly lower than that of phosphorus, due to the paired electrons in its 3p sub-level.

Question 21

What it is metallic bonding?

Answer 21

Is it the strong electrostatic attraction between delocalised electrons and cations, the positive ions.

Question 22

What is giant metallic bonding?

Answer 22

It is the regular arrangements of cations in all metals.

Question 23

What are the three giant covalent lattices?

Answer 23

• Diamond
• Graphite
• Graphene

Question 24

What are the physical properties of giant metallic lattices?

Answer 24

• good conductor of heat - free moving electrons in the lattice
• melting & boiling points are usually quite high due to strong attraction
• malleability & ductility - delocalised electrons protect cations from repelling
• metals do not dissolve in, rather they react in water

Question 25

What are the physical properties of giant covalent lattices?

Answer 25

• high melting points
• insoluble
• very hard
  Because strong covalent bonds between atoms require lots of energy to overcome, so they are not broken readily
• electrical insulators - generally no charged particles are free to move

Question 26

Which elements in period 2 & 3 are giant metallic structures? why?

Answer 26

Na, Mg, Al, Li, Be - high energy needed to overcome these bonds because of the high number of delocalised electrons in the lattice, which increase the strength of metallic bond.

Question 27

Which elements in period 2 & 3 are giant covalent structures? why?

Answer 27

Si, B, C- very high needed to overcome these bonds because of the strong covalent bonds.

Question 28

Which elements in period 2 & 3 are simple molecular structures? why?

Answer 28

N, Ne, O, F, P, S, Cl, Ar - little energy needed to overcome these weak intermolecular forces