Question
(b) Bromine and gallium are in period 4 of the periodic table. The electronegativity of the elements in period 4 changes across the period. Explain how the electronegativity changes from gallium to bromine. (4)
Answer
4.1
(236 Votes)
Benedict
Elite · Tutor for 8 years
Answer
The electronegativity increases from Gallium to Bromine across the 4th period of the periodic table because the number of protons in the nucleus increases. As protons are increased, the effective nuclear charge experienced by bonding pairs of electrons also increases and thus causes the increase in electronegativity as we move from left to right, i.e., from Ga to Br across the period. Hence, Bromine has higher electronegativity than Gallium.
Explanation
## Step 1: Identify the Elements in QuestionFirst, we need to identify the elements Gallium (Ga) and Bromine (Br) in Period 4 of the Periodic Table. Gallium is on the left and Bromine is on the right in the same period indicating that they have the same number of energy shells. ## Step 2: Understand Physical Properties of ElementsBromine and Gallium are both in the same period but still, they have different configurations due to their location in the periodic table. Element turn from metal to non-metal as they move from left to right (like in our case from Gallium to Bromine).## Step 3: Identify Trend in ElectronegativityThe electronegativity of elements generally increases with moving across a period from left to right, as we move from Gallium to Bromine. This occurs because the effective nuclear charge experienced by the bonding pairs of electrons increases due to an increase in the number of protons in the nucleus, and electric shielding remains approximately constant as electrons are added to the same shell. ### For formulas, here's the simple approach we use to explain this increase: Midnight electronegativity = nuclear charge / distance^2 (Here nuclear charge is generally the number of protons and distance is the nucleus-electron distance)