V K Sally and R Goel Solutions for Chapter: Structure of Atom, Exercise 3: ASSIGNMENTS FOR FORMATIVE ASSESSMENT

An atom has mass number 14 and 8 neutrons in its nucleus. The atom is an isotope of

An element has mass number $31$ and atomic number $15$. The number of electrons, protons and neutrons in it are respectively

Rutherford’s experiment of scattering of  $\mathrm{\alpha }$-particles showed for the first time that an atom has a:

Which of the following classes of elements differ in their chemical properties?

${}_{19}{}^{39}\mathrm{K}$ changes to its ions by the loss/gain of electrons. How many electrons will it lose or gain?

${}_{19}{}^{39}\mathrm{K}$ changes to an ion of the nearest noble gas. What kind of change occurs when it forms a K ion?

Name the part of the atom, where most of its mass is concentrated.

An element [${}_8{}^{16}\mathrm{O}$] acquires two protons by nuclear bombardment. To which element does it change.