If the value of `E=-78.4 "kcal//mol"`, the order of the orbit in hydrogen atom is-

Options

A. `4`
B. `3`
C. `2`
D. `1`

Answer

C

Explanation

`E=-78.4 kcal//mol`
`E_(n)=-313.6xx(Z^(2))/(n^(2))kcal//mol`
for `H` atoom `Z=1 " "-78.4=313.6xx(1)/(n^(2))`
`n^(2)=(313.6)/(78.4)" "n=2`