Question

Elements have been arranged in the following sequence on the basis of their increasing atomic masses. F,Na,Mg,Al,SI,P,S,Cl,Ar,K (a) pick two sets of elements which have similar properties. (b) the given sequence represents which law of classification of elements.

Answer 1

Answer:

(a) (i) F and Cl (ii) Na and K

(b) Newlands law of octaves

Hope it helps you

Answer 2

The given question can be answered as follows:

Part (a)

• Elements that belong to the same group in the periodic table, have the same valency and show similar chemical and physical properties.
• Two sets of elements that have similar properties from the given elements are:

1. Fluorine (F) and Chlorine (Cl) (group 17 in the periodic table).
2. Sodium (Na) and Potassium (K)  (group 1 in the periodic table).

Part (b)

• The given sequence of elements, that is, F, Na, Mg, Al, Si, P, S, Cl, Ar, K have been arranged in a sequence according to the law of octaves.
• The law of octaves suggested that on arranging elements according to their atomic weight, elements with similar properties were seen after every seven elements.