Question

An element X exists in three forms A, B and C in the ratio 1:2:3. If C has 10 protonsand the number of neutrons in A, B and C are 10, 11 and 12 respectively,Give the following:(i) Representation of form C of the element X(ii) Electronic configuration of form B of the element(iii) Calculate the average atomic mass.

Answer 1

x21 +ANSWER

(i) Ne-22

(ii)1s2s22p6

(iii)21.3

An element X exists in three forms A, B and C in the ratio 1:2:3. If C has 10 protons and the number of neutrons in A, B and C are 10, 11 and 12 respectively,Give the following:(i) Representation of form C of the element X(ii) Electronic configuration of form B of the element(iii) Calculate the average atomic mass.

(i)C  has 10 protons and 12 neutrons so a mass of 10 +12 =22

element 10 is Neon (Ne) so this isotope is Ne-22

(ii) they all have the sane atomic number so the same number of electrons

with an electronic structure of 1s2s22p6

(iii) A weighs 20, B weighs 21, C weighs 22

the ratio is 1:2:3

weighted average weight is therefor

(1X20 +2X21 +3X22)/6 =21.3