From the elements Li, K, Mg, C, Al, S identify the

(a) elements belonging to the same group.

(b) element which has the tendency to lose two electrons.

(c) element which prefers sharing of electrons to complete its octet.

(d) most metallic element.

(e) element that forms acidic oxide.

(f) element that belongs to group 13.

Let's analyze each element based on its position in the periodic table and chemical properties:

• Lithium ($Li$) and Potassium ($K$): Both are alkali metals in Group 1. They have 1 valence electron and show similar chemical properties.
• Magnesium ($Mg$): Located in Group 2, Period 3. It has an electronic configuration of $2, 8, 2$. It loses 2 electrons to achieve a stable octet configuration ($Mg^{2+}$).
• Carbon ($C$): Located in Group 14, Period 2. It has 4 valence electrons. It is energetically unfavorable to gain or lose 4 electrons, so it shares electrons to complete its octet.
• Potassium ($K$): It is below Lithium in Group 1. Metallic character increases down a group, making Potassium highly electropositive and the most metallic element listed.
• Sulfur ($S$): A non-metal in Group 16. On burning, it forms sulfur dioxide ($SO_2$), which dissolves in water to form sulfurous acid ($H_2SO_3$), an acidic oxide.
• Aluminium ($Al$): Located in Group 13, Period 3. It has an electronic configuration of $2, 8, 3$ and forms $Al^{3+}$ ions.