Question

1. fill in the blanks in the data table below regarding the periodic table of the elements.

group/family number	1a	2a	3a	4a	5a	6a	7a	8a
electron config. ends in			$s^2p^1$
number of valence electrons

Explanation:

Step1: Analyze Group 1A (Alkali Metals)

Alkali metals are in Group 1A. Their electron configuration ends with \( ns^1 \) (where \( n \) is the principal quantum number). The number of valence electrons is 1.

Step2: Analyze Group 2A (Alkaline Earth Metals)

Alkaline earth metals are in Group 2A. Their electron configuration ends with \( ns^2 \). The number of valence electrons is 2.

Step3: Analyze Group 3A

Group 3A elements have electron configuration ending with \( ns^2np^1 \) (given in the table). The number of valence electrons is \( 2 + 1 = 3 \).

Step4: Analyze Group 4A

For Group 4A, the electron configuration ends with \( ns^2np^2 \). The number of valence electrons is \( 2 + 2 = 4 \).

Step5: Analyze Group 5A

Group 5A elements have electron configuration ending with \( ns^2np^3 \). The number of valence electrons is \( 2 + 3 = 5 \).

Step6: Analyze Group 6A

Group 6A elements have electron configuration ending with \( ns^2np^4 \). The number of valence electrons is \( 2 + 4 = 6 \).

Step7: Analyze Group 7A (Halogens)

Halogens are in Group 7A. Their electron configuration ends with \( ns^2np^5 \). The number of valence electrons is \( 2 + 5 = 7 \).

Step8: Analyze Group 8A (Noble Gases)

Noble gases are in Group 8A (except He, which has \( 1s^2 \); others have \( ns^2np^6 \)). The number of valence electrons is 8 (for Ne, Ar, etc.) or 2 (for He), but generally, noble gases have a full valence shell with 8 valence electrons (except He).

Now, let's fill the table:

Group/Family Number	Group/Family Name	Electron config. ends in	Number of Valence electrons
2A	Alkaline earth metals	\( ns^2 \)	2
3A	-	\( ns^2np^1 \)	3
4A	-	\( ns^2np^2 \)	4
5A	-	\( ns^2np^3 \)	5
6A	-	\( ns^2np^4 \)	6
7A	Halogens	\( ns^2np^5 \)	7
8A	Noble gases	\( ns^2np^6 \) (or \( 1s^2 \) for He)	8 (or 2 for He)

Answer:

The filled table (key parts) is as above. For each group:

• 1A: Electron config ends in \( ns^1 \), Valence e⁻ = 1
• 2A: Electron config ends in \( ns^2 \), Valence e⁻ = 2
• 3A: Given \( ns^2np^1 \), Valence e⁻ = 3
• 4A: Electron config ends in \( ns^2np^2 \), Valence e⁻ = 4
• 5A: Electron config ends in \( ns^2np^3 \), Valence e⁻ = 5
• 6A: Electron config ends in \( ns^2np^4 \), Valence e⁻ = 6
• 7A: Electron config ends in \( ns^2np^5 \), Valence e⁻ = 7
• 8A: Electron config ends in \( ns^2np^6 \) (or \( 1s^2 \)), Valence e⁻ = 8 (or 2)