I) Name the Chemical family name in which Elements A, B and C belong. ii) Element X has atomic number 8. Using a tick (✓) show the position of X. iii) Identify the Most reactive metal. Give reason.

i) Name the Chemical family name in which Elements A, B and C belong.
Elements A, B, and C are located in Group I of the periodic table. This group, excluding hydrogen, consists of highly reactive metals.
The chemical family name is:

• Alkali Metals

ii) Element X has atomic number 8. Using a tick (✓) show the position of X.
Element X with atomic number 8 is Oxygen. Oxygen is located in Period 2, Group VI (or 16) of the periodic table.
In the provided diagram:

• The first column (A, B, C) is Group I.
• The second column (D) is Group II.
• The third column (E) is Group III.
• The fourth column (F) is Group IV.
• The fifth column (G) is Group V.
• The sixth column (S, P) is Group VI.
• The seventh column (R) is Group VII.
• The eighth column (Q) is Group VIII. Assuming the top row of elements E, F, G, S, R corresponds to Period 2, then element S is in Group VI, Period 2. This is the position of Oxygen.

The position of X (Oxygen) is:

$$\begin{bmatrix} \text{I} & \text{II} & \text{III} & \text{IV} & \text{V} & \text{VI} & \text{VII} & \text{VIII} \\ \text{A} & & & & & & & \\ \text{B} & \text{D} & \text{E} & \text{F} & \text{G} & \boxed{\text{S}\checkmark} & \text{R} & \\ \text{C} & & & & & \text{P} & & \text{Q} \end{bmatrix}$$

iii) Identify the Most reactive metal. Give reason.
Metallic reactivity increases as you move down a group and decreases as you move across a period from left to right. This is because larger atoms in a group have their valence electrons further from the nucleus, making them easier to lose.
Among the given elements, A, B, and C are in Group I, which are metals. Element C is positioned lowest in Group I.

• The most reactive metal is C.
• Reason: Metallic reactivity increases down a group because the atomic radius increases, leading to weaker attraction between the nucleus and the outermost electron. This makes it easier for the atom to lose its valence electron and form a positive ion.