Which one of the following is the electronic configuration of the bivalent calcium Ca²⁺?

Consider the following four particles

1. Alpha particle

2. Proton

3. Electron

4. Neutron

Which of the following is the correct sequence in which their rest masses increase?

Consider the following statements:

$1.$ The energy of the electrons in the orbit is quantized.
$2.$ Electrons revolve only in those orbits for which angular momentum is not an integral multiple$\frac{h}{2\mathrm{\pi }}$.
$3.$ The electrons don't revolve in different orbits around the nucleus.

$4.$ The electrons emit energy during revolution due to the presence of coulombic forces of attraction.

Which of the statements given above is/are correct about Bohr's model of an atom?

Some sub-nuclear particles are

1. antiproton

2. $\mu$-meson

3. $\pi$-meson

4. neutrino

5. positron

Increasing order of year of discovery is (starting from the earliest)