Question

Which of the following is true ?
A. The ionisation energuy of a hydrogen -like species in its ground state is equal to the magnitude of energy of the orbit having `n = 1`
B. The ionisation energy of a hydrogen -like species in its ground state increases in principle to the positive charge in its nucleus
C. According to the unsertainty principle `Delta p Delta s le(h)/(4pi)`
D. The energy of an electron in a orbit of a multielectron atom depends only on the principle quantum number n

Answer 1

Correct Answer - A
For ionisation `n_(2) = prop ` Hence
`Delta E = R((1)/(n_(1)^(2)))`
b . The ionisation energy in proportion to the square of the charge in the nucleuws as is evident from the expression
`R = (2pi^ (2)m((Ze^(2))/(4 pi epsilon_(0)))^(2))/(h^(3)c)`
`Delta barE _(1) = R`
c. The correct expression is `Delta p Delta s ge (h)/(4pi)`
d. For a multi -electron atom the energy of an orbital depends on both principle and azimuthal quantum number .The largwe tyhe value of `n = l`, the large the value of n, the large the energy