An atom has the electronic configuration of 1 s^2 ,2 s^2 2 p^6 , …

MCQ

An atom has the electronic configuration of $1{s^2},2{s^2}2{p^6}$, $3{s^2}3{p^6}3{d^{10}},4{s^2}4{p^5}$. Its atomic weight is $ 80.$ Its atomic number and the number of neutrons in its nucleus shall be

✓
$35 $ and $45$
B
$45$ and $35$
C
$40$ and $40$
D
$30$ and $50$

✓

Answer

Correct option: A.

$35 $ and $45$

a
(a) $_{35}B{r^{80}}\, = \,\,1{s^2}\,2{s^2}\,2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^5}$

$A = \,80$, $Z = \,35$, $N = \,?$

$N = A - Z = 80 - 35 = 45$

atomic number (Proton) is $35 $ and no. of neutron is $45.$

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