Question

Electron gain enthalpy increases or decreases in a period and why?

Answer 1

Across a period tell me nuclear charge increases or decreases??

Answer 2

nuclear charge increase i think

Answer 3

Yes.

The atomic and ionic radii decreases across the period and the nuclear charge increases across the period,

So Electron Gain Enthalpy increases in periods..

Answer 4

it will become more negative

Answer 5

@waterineyes

Answer 6

why it is said more negative...???

Answer 7

bcoz it is exothermic i think

Answer 8

Yes it is a negative measure by saying that it increases it means it becomes more negative..

Answer 9

then down the group it decreases

Answer 10

@waterineyes

Answer 11

but cl is more negative than f why???

Answer 12

See, when nuclear charge increases then it becomes difficult to extract an electron from the atom because more positive will attract the electrons towards itself..
So, more amount of heat is required to take the electron from the atom..

Answer 13

then down the group it decreases or not @waterineyes

Answer 14

I have studied all these things 4 years ago so my mind is not very smart in this..

You will probably say that Cl should have lesser negative than F but there is some other reason for this also...

Answer 15

Down the group it decreases... and this is what I am sure about..

Answer 16

wat is that reason lol

Answer 17

Engineering in Electronics And Communication..

Answer 18

it is an exceptional case where fluorine is small atom, and so it's electron density is very high. Adding an additional electron is therefore not quite as favorable as for an element like chlorine where the electron density is slightly lower (due to electron-electron repulsion between the added electron and the other electrons in the electron cloud).