Periodicity

Question 1

Explain electrical conductivity from sodium to aluminium

Answer 1

• increases
• Number of delocalised electrons increases
• More electrons free to carry current

Question 2

Explain melting point of sodium to aluminium

Answer 2

• Increases
• Atom size ⇧
• Charge ⇧
• attraction between positive ions and delocalised electrons ⇧
• More energy required to separate them

Question 3

explain electronegativity across period 3

Answer 3

• increases
• PN ⇧
• same shielding
• ability to attract electron density from covalent bond

Question 4

explain first ionization energy across period 3

Answer 4

• increases
• PN ⇧
• Same shielding
• ⇧ nuclear attraction
• more energy required to remove electrons

Question 5

Explain atomic size across period 3

Answer 5

• decreases
• PN ⇧
• same shielding
• Stronger attraction between nucleus and electrons