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

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?

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?

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.

Write the names and symbols of two very reactive metals belonging to group 1 of the periodic table. Explain by drawing electronic structure, how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.