Structure of At...

Radioactivity can be effected by :

$$\alpha,\beta$$ and $$\gamma$$ radiations come out of a rodiactive substance

According to the nuclear reaction $$_4 Be + \ _2 He^4 \longrightarrow \ _6 C^{12} + \ _0 n^1$$, mass number of $$(Be)$$ atom is:

Nitrogen has the electronic configuration $$1s^2, 2s^2, 2p_x^1, 2p_y^1, 2p_z^1$$ and not $$1s^2, 2s^2, 2p_x^2, 2p_y^1, 2p_z^0$$ which is determined by

The expression for Bohr's radius of an atom is 

The ratio of the radii of the first three Bohr orbits is:

The radius of the first Bohr orbit of hydrogen atom is $$r$$. The radius of the $$3^{rd}$$orbit would be:

If an isotope of hydrogen has two neutrons in its atom, its atomic number and atomic mass number will respectively be:

An element $$_{96}X^{227}$$ emits $$4\alpha$$ and $$5\beta$$ particles to form new element Y. Then atomic number and mass number of Y are:

A radium $$_{88}Ra^{224}$$ isotope, on emission of an $$\alpha$$ -particle gives rise to a new element whose mass number and atomic number will be: