To accommodate the view that matter is made up to $5$ elements only, a scientist proposed the following hypothesis; that atoms can have a maximum principal quantum number $n _{\operatorname{man}}$ and no higher. Then, which of the following statements must be true ?
$n _{\max }=1$, and electrons have spin
$n _{\max }=2$, and electrons have spinless but nevertheless obey the Pauli Exclusion principle.
$n_{\max }=3$, and electrons are spinless but nevertheless obey the Pauli Exclusion principle.
$n_{\max }=4$, and electrons have spin
The first line in the Lyman series has wavelength $\lambda $ . The wavlength of the first line in Balmer series is
In the result of the Geiger-Marsden experiment, by which the trajectory of the $\alpha $ -particle can be calculated ?
What does it mean if the $\alpha -$ particle passes through the foil of gold ?
Assertion: The specific charge of positive rays is not constant.
Reason: The mass of ions varies with speed.
According to the Rutherford’s atomic model, the electrons inside the atom are