The elements A, B and C belongs to groups 1, 14 and 17 repectively of the periodic table.

(a) Which two elements will form a covalent compound?

(b) Which two elements will form an ionic compound?

An element X from group 2 of the periodic table reacts with an element Y from group 17 to from a compound.

(a) What is the nature of the compound formed.

(b) State whether the compound formed will conduct electricity or not.

(c) Give the formula of the compound formed.

(d) What is the valency of element X?

(e) How many electrons are there in the outermost shell of an atom of element Y?

The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):

(i)Select the letter which representsan alkali metal.

(ii) Select the letter which represents a noble gas.

(iii) Select the letter which represents a halogen.

(iv) What type of bond is formed between a and e?

(v) What type of bond is formed between d and e?

Find the neutral atom in the periodic table which has the same number of electrons as K+ and Cl-. What is this number?

Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electron shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound. This ionic compound is added in a small amount to almost all vegetables and dishes during cooking. Oxides of elements A and B are basic in nature while those of elements E and F are acidic. The oxide of element D is, However, almost neutral. Based on the above information, answer the following questions:

(a) To which group or period of the periodic table do these elements belongs?

(b) What would be the nature of compound formed by a combination of elements B and F?

(c) Which two of these elements could definitely be metals?

(d) Which one of the eight elements is most likely to be found in gaseous state at room temperature?

(e) If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write the formula of the compound formed by the combination of C and G.