a. Calculate the radius of Bohr's first orbit for hydrogen atom and the energy of electron in this orbit .
b. Calculate the Bohr's radius for the fifth orbit of the hydrogen atom

Answer

A, B, C

Explanation

a.`r_(n) = (n^(2)h^(2))/( 4pi^(2)me^(2)K)`
`r_(1) = ((1)^(2)(6.62 xx 10^(-34))^(2))/(4)`
`= (3.14)^(2)(9.109 xx 10^(-31))(1.6 xx 10^(-9))^(2)(9 xx 10^(9)) = 6.529 xx 10^(-19) m = 0.529 Å`
`E = (Kze^(2))/(2r)`
`= -(( 9 xx 10^(9))(1)(1.6 xx 10^(-19))^(2))/(2 xx 0.529 xx 10^(-10))`
`=-2.178xx10^(-18)J`