Question

Which element of the third period had the highest first ionization energy?

•silicon
•sulfur
•argon
•sodium

Answer 1

C.) Argon

Step-by-step explanation:

This is because ionisation energy increases as we move from left to right in a period. Argon presents in the right most column and Argon is a novel gas and has 8 electrons in outermost orbital. So, it is highly stable. I hope I helped! ^-^