Question

1. Element J was found to have the following ionization energies (in kJ/mol)

1st IE	2nd IE	3rd IE	4th IE	5th IE	6th IE
631	1235	2389	7099	8844	10720

1. How many valence electrons does element J have? Explain. (2)

2. If element J is found in the fourth period, identify element J. (1)

3. Write the electronic configuration for element J. (1)

4. Write complete sets of quantum numbers for each of the valence electrons (i.e. n, l, and m_l) that you determined in part i). (3)

Answer 1

From the given table, it is clear that the difference between 3rd and 4th IE values is more. Hence, the element can have 3 number of valence electrons in its sub shell.

The element with 3 valence electrons and present in the 4th period is, Gallium (Ga)

The electronic configuration of Gallium is,  Ar 3d¹⁰ 4s² 4p¹ .

For 4s electrons, n=4 , l=0 & ml = 0

For 4p electron , n=4, l=1 & ml=-1,0,+1.