Sure, let's go through each part of the question step-by-step:
### 1. The element \( A \) belongs to the second period and 17th group, and element \( B \) belongs to the third period and second group of the periodic table.
a. Write the subshell electronic configuration of \( A \).
Since \( A \) is in the second period and 17th group, it is Fluorine (F) with an atomic number of 9. The electronic configuration of Fluorine is:
[tex]\[ \text{1s}^2 \, 2\text{s}^2 \, 2\text{p}^5 \][/tex]
b. To which block does \( B \) belong? What is its valency?
Element \( B \) is in the third period and second group, which identifies it as Magnesium (Mg) with an atomic number of 12. Magnesium belongs to the s-block and its typical valency is +2.
c. Give the formula of the compound formed by \( A \) and \( B \).
The compound formed when Magnesium (Mg) and Fluorine (F) combine is magnesium fluoride, which has the chemical formula:
[tex]\[ \text{MgF}_2 \][/tex]
### 2. Arrange the subshells in the correct order of electron filling:
Given subshells: \(\text{4s, 3d, 2p, 3s, 2s, 1s, 3p, 4p}\)
The correct order of electron filling according to the Aufbau principle and Hund's rule is:
[tex]\[ \text{1s}, \, \text{2s}, \, \text{2p}, \, \text{3s}, \, \text{3p}, \, \text{4s}, \, \text{3d}, \, \text{4p} \][/tex]
### 3. How many electrons can be accommodated in the \( f \) subshell?
The f subshell can accommodate a maximum of:
[tex]\[ 14 \text{ electrons} \][/tex]
### 4. Analyze the table and answer the questions.
[tex]\[
\begin{array}{|c|c|}
\hline
\text{Element (Symbols are not real)} & \text{Atomic number} \\
\hline
P & 11 \\
\hline
Q & 18 \\
\hline
R & 16 \\
\hline
S & 26 \\
\hline
\end{array}
\][/tex]
a. Which of the above is a first group element?
Element \( P \) has an atomic number of 11, which is Sodium (Na). Sodium is in the first group of the periodic table.
b. What is the valency of \( R \)?
Element \( R \) has an atomic number of 16, which is Sulfur (S). Sulfur commonly exhibits a valency of -2.
c. Give the formula of the compound when \( P \) combines with \( R \).
When Sodium (Na) combines with Sulfur (S), the compound formed is sodium sulfide, with the chemical formula:
[tex]\[ \text{Na}_2\text{S} \][/tex]
d. Which of the above shows different oxidation states?
Element [tex]\( S \)[/tex] has an atomic number of 26, which is Iron (Fe). Iron exhibits various oxidation states, most commonly +2 and +3.
