Which element in period 4 has the highest electronegativity? potassium calcium copper bromine

Bromine has the highest electronegativity in period 4 of the periodic table.

Explanation:

Electronegativity is defined as the tendency of an atom to attract the shared pair of electrons towards itself whenever a bond is formed.

This property of an atom increases as we move from left to right in a period because the number of charge on the nucleus gets increased.

But this property decreases as we move from top to bottom in a group because electrons get add up in the new shells which make them further far away from the nucleus.

For the given options:

Potassium is present in Group 1, Period 4 of the periodic table.

Calcium is present in Group 2, Period 4 of the periodic table.

Copper is present in Group 11, Period 4 of the periodic table.

Bromine is present in Group 17, Period 4 of the periodic table.

Hence, bromine will have the highest electronegativity in Period 4.

1 is the answer to this problem