Question Text
Question 2 :
What is the SI prefix for $10^{-12}$ multiples and submultiples of a unit?
Question 5 :
The total number of valence electrons in $4.2g$ of ${N}_{3}^{-}$ ions are:
Question 6 :
About the number of subatomic particles in an ion of $_{16}^{32}{{S}^{2-}}$, which is/are true?<br/>I. $16$ protons<br/>II. $14$ neutrons<br/>III. $18$ electrons
Question 7 :
A magnesium ion has a net positive charge while the magnesium atom has no charge.<br/>
Question 8 :
The ratio of the radii of hydrogen atom and its nucleus is ~ $10^{5}$. Assuming the atom and the nucleus to be spherical, what will be the ratio of their sizes ?
Question 9 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 10 :
Which of the following is true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons.
Question 11 :
Rutherford’s $\alpha$–particle scattering experiment showed that
(i) electrons have negative charge
(ii) the mass and positive charge of the atom is concentrated in the nucleus
(iii) neutron exists in the nucleus
(iv) most of the space in atom is empty
Which of the above statements are correct?