Atomic Mass and Composition of Nucleus

$1 \mathrm{u}=$_____$\times {10}^{-27 }\mathrm{kg}$

The unified atomic mass unit, which is depicted by u, is equal to the ${\frac{1}{12}}^{\mathrm{th}}$ of the mass of an atom of _____-$12$ isotope.

Isotopes that emits radiation are called _____. (radioisotope / stable isotope)

Assertion : $\mathrm{C}$ and $\mathrm{Si}$ both have same lattice structure, having $4$ bonding electrons in each. However, $\mathrm{C}$ is insulator where as $\mathrm{Si}$ is intrinsic semiconductor.
Reason : The four bonding electrons in the case of $\mathrm{C}$ lie in the second orbit, whereas in the case of $\mathrm{Si}$ they lie in the third.

Which of the following gives the correct number of protons and neutrons in a nucleus of carbon-$14 \left({}_6{}^{14}C\right)?$

The mass number of an atom $A=38$ and its electronic configuration is $1s^2 2 s^2 2p^6 3s^2 3p^4$. The number of neutrons and protons in the nucleus will be

${}_{10}{}^{22}\mathrm{Ne}$ nucleus, after absorbing energy, decays into two $\alpha$-particles and an unknown nucleus. The name of unknown nucleus is _____.

When atoms are bombarded with the alpha particles, only a few in a million suffer deflection and the others pass out undeflected. This is because

Rutherford's experiment on scattering of particles showed that an atom has

Nucleus of an atom consists of protons and electrons.

The number of radioactive isotope of Hydrogen and total number of isotopes of Hydrogen are:

The proton and neutron are collectively called as

The nucleus of helium contains

............... has a pair of isomers

The nucleus consists of

The atomic number is equivalent to which of the following?

An unknown chemical element is presented by the following formula: ${}_Z^{A}X.$ What is the name of index A?

The atomic mass of an element is not a whole number because

The triad of nuclei that is isotonic is

In which of the species the number of neutrons is equal to the number of electrons ?