# Choose the element in each of the sets you would expect to have the highest IE2

• CMATT
In summary, the element in each set with the highest IE2 is K. This is because after the first ionization, K attains the electron configuration of the nearest noble gas, Argon, making it highly stable. In comparison, the other elements (Be, Mg, Ca, and Al) have an outer shell electron configuration of ns1 after the first ionization, making it easier for them to ionize and achieve stability. Therefore, their IE2 would be lower than that of K.

## Homework Statement

Choose the element in each of the sets you would expect to have the highest IE2.

a. K
b. Be
c. Mg
d. Ca
e. Al

## The Attempt at a Solution

I do not understand why it is K ...I kind of guessed by using my Ionization Energy diagram that shows the trend on the periodic table as:

--------> IE increases across a period/row
|
|
|
IE decreases down a group

Can someone please explain why K is correct?

What do you know about number of valence electrons in elements? How does it depend on the the element position in the periodic table? Why do the valence electrons are valence electrons?

That's a general trend.But there are exceptions. Besides you have to compare IE2.So this can't be used.
After 1st Ionisation K attains the EC of nearest noble gas i.e. Argon which means it is highly stable.So IE2 of K is highest.
On the other hand if you see Be,Mg,Ca then the outer shell EC of these elements after 1st ionisation is ns1.So they can easily ionise to gain stability.

CMATT said:

## Homework Statement

Choose the element in each of the sets you would expect to have the highest IE2.

a. K
b. Be
c. Mg
d. Ca
e. Al

## The Attempt at a Solution

I do not understand why it is K ...I kind of guessed by using my Ionization Energy diagram that shows the trend on the periodic table as:

--------> IE increases across a period/row
|
|
|
IE decreases down a group

Can someone please explain why K is correct?