The atomic masses of three elements `X,Y` and `Z` having similar chemical properties are 7,23 and 39 respectively
(a) Calculate the average atomic mass of elements `X` and `Z`
(b) How does the averge atomic mass of elements `X` and `Z` compare with the atomic mass of element `Y`
(c) Which law of classification of elements is illustrated by this example?
(d) What could the elements `X,Y` and `Z` be?
(e) Give another example of a set of elements which can be classified according to this law.

Answer

(a) 23 (b) The average atomic mass of elements `X` and `Z` is equal to the atomic mass of element `Y` (c) Dobereiner's law of triads (d) `X` is lithium, `Y` is sodium `Z` is potassium (e) Chlorine, Bromine, Iodine

Explanation

NA