The Periodic Table

Question 1

Traits of groups

Answer 1

1. Elements inside have similar chemical properties
2. Same valence electron no., but the proton number increases
3. Size increases down a group since there are more valence shells available
4. Group Number corresponds to the charge

Question 2

Traits of Periods

Answer 2

1. Horizontal
2. Elements have the same number of valence shells
3. Size decreases across a period, since the valence shell stay the same but proton no, increases, increases the charge
4. Metallic Property decreases
5. Ionic property of compounds formed decreases
6. Oxides change from basic to amphoteric to acidic
7. Bonding changes from metallic to covalent

Question 3

Metalloids

Answer 3

• Express both metal and non-metal properties
• Semi-Conductors

Question 4

Group 1 Metals (Alkali Metals)

Answer 4

Physical Properties
1. Soft, silvery and shiny -> due to weak metallic bonds between them
2. MP decreases down the group
3. Weak MP and BP as less energy is required to break apart the weak metallic bonds between them (compared to transition metals
4. Low Densities
Chemical Properties
1. Reactivity increases down a group since there is a greater tendency for electrons to be lost due to the increase in valence shells, further away from the positively charged nucleus
2. Reacts with oxygen
3. Reacts with water to form an alkaline substance
4. Reacts with chlorine
5. Li burns red, Na burns yellow and K burns lilac

Question 5

Group 17 (Halogens)

Answer 5

Physical Properties
1. Exist as diatomic molecules
2. Colour darkens down the group
3. Low MP and BP as they are covalently bonded, weak intermolecular forces or energy
4. MP and BP increase down a group as more energy is required to break apart the intermolecular forces that increase
Elements Physical
Flourine -> Pale Yellow
Chlorine -> Yellow-Green (MP -101, BP 34)
Bromine -> Reddish-Brown (MP -7, BP 59)
Iodine -> Violet (MP 114 BP 184)
Chemical Properties
1. Reactivity decreases down the group
2. Displacement reaction -> More reactive (down) displaces/replaces the one which is less reactive (higher up)
3. Tends to be oxidising agents as they exist as anions

Question 6

Transition Elements (Groups 3-12)

Answer 6

Physical Properties
1. Hard, Shiny
2. Good Thermal and Electrical conductors
3. High MP and BP compared to grp 1
4. High densities
Chemical Properties
1. No fixed OS
2. Mostly unreactive
3. Coloured ions
4. Forms coloured compounds
5. Catalysts (Fe Haber Process, Ni Margarine)

Question 7

Group 18 (Noble Gases)

Answer 7

Physical Properties
1. Monoatomic non-metals
2. Low MP and BP due to covalent bonds
3. Increase in MP and BP
4. Exist as colourful gases at room temperature
Chemical
1. Inert and least reactive since the valence shells are all full
2. Insoluble in water