list all the elements in group I(A), ii(A) and period 3 in order of their increasing atomic number

Answer 1

Group I(A) elements (Alkali Metals) in order of increasing atomic number:
1. Hydrogen (H)
2. Lithium (Li)
3. Sodium (Na)
4. Potassium (K)
5. Rubidium (Rb)
6. Cesium (Cs)
7. Francium (Fr)

Group II(A) elements (Alkaline Earth Metals) in order of increasing atomic number:
1. Beryllium (Be)
2. Magnesium (Mg)
3. Calcium (Ca)
4. Strontium (Sr)
5. Barium (Ba)
6. Radium (Ra)

Period 3 elements in order of increasing atomic number:
1. Sodium (Na)
2. Magnesium (Mg)
3. Aluminum (Al)
4. Silicon (Si)
5. Phosphorus (P)
6. Sulfur (S)
7. Chlorine (Cl)
8. Argon (Ar)

Answer 2

state the electronic configuration of the following elements: Barium, Silicon, sulfur, lithium and potassium.

Answer 3

The electronic configurations of the given elements are as follows:

Barium (Ba): 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2

Silicon (Si): 1s2 2s2 2p6 3s2 3p2

Sulfur (S): 1s2 2s2 2p6 3s2 3p4

Lithium (Li): 1s2 2s1

Potassium (K): 1s2 2s2 2p6 3s2 3p6 4s1