Question

1. Arrange the following elements in order of decreaing first ionization energy starting with the highest.

S Ca F Rb Si

2. Arrange the ions in order of increasing ionic radius starting with the smallest.

O2- N3- Mg2+ F- NA+

1. Arrange the following atoms in order of decreasing atomic size starting with the largest.

Ca Rb S Si Ge F

Answer 1

1. Order of first ionization energy starting with the highest.

F>S>Si>Ca>Rb

17.42 ev Fluorine F

10.36 ev Sulfur S

8.15 ev Silicon   Si

6.11 ev Calcium Ca

4.18 ev Rubidium Rb

2. Order of increasing ionic radius starting with the smallest.

The given ions are all 1s22s22p2 systems. So, with more negatively charged ion will have bigger radius and more positively charged ion will have smaller radius.

So, the order is-

Mg2+ < Na+ < F- < O2- < N3-

3. Order of decreasing atomic size starting with the largest.

From the periodic properties, the order is-

Rb > Ca > Ge > Si > S > F