Question

Name the element with highest and lowest ionization energy in first three period ​

Answer 1

Answer:

The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.....

Answer 2

Answer:

Helium { He} and sodium {Na}.

Explanation:

the amount of energy required for an isolated gaseous atom to lose an electron in its ground state is known as ionisation energy.......

1) the highest ionisation energy element is Helium (He).

2) the lowest ionisation energy element is sodium (Na).