Question

Element A,B,C,D and E have atomic mass numbers 4, 9 , 13 , 17 and 20 respectively. Write thier electronic distribution. Determine thier valency. Classify them as metal or non- metal

Answer 1

if given are atomic no.

A 2,2 Val 2 metal
B 2,7 Val 1 nonmetal
C 2,8,3 Val 3 metal
D 2,8,7 Val 1 nonmetal
E 2,8,8,2 val2 metal

Answer 2

Hey friend !!

Here is your answer..

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Electronic configuration :

● A -- 2 , 2

● B -- 2 , 7

● C -- 2 , 8 , 3

● D -- 2 , 8 , 7

● E -- 2 , 8 , 8 , 2

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Valency :

● A -- 2

● B -- 1

● C -- 3

● D -- 1

● E -- 2

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A , C and E are metals while B and D are non-metals.

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Hope it helps.

#Pragya_Singh