Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 1

HARD

9th CBSE

IMPORTANT

Earn 100

An atom of an elements is represented as ${}_{11}^{23}X$ .
(i) What is the number of proton in X?
(ii) What is the number of neutrons X?
(iii) How are the electrons distributed around the nucleus of X?

Important Questions on Structure of Atom

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 2

What do you understand by the term electronic configuration? State Bohr-Bury's scheme of electronic configuration.

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 3

State three ways in which a proton differs from an electron.

MEDIUM

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 4

State Bohr's model of the structure of atom.

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 5

In the gold foil experiment of Geiger and Marsden, that paved the way for Rutherford's model of an atom.

~

1.00% of the

α

-particles were found to deflect at angles

> 50 °

, If one mole of

α

-particles were bombarded on the gold foil, calculate the number of

α

-particles that would deflect at angles less than 50

°

.

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 6

Complete the table given below on the basis of information available in the symbols given below.
(A) ${}_{17}^{35}{Cl}$
(B) ${}_{6}^{12}C$
(C) ${}_{35}^{81}{Br}$

Element	n_p	n_n

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 7

Enlist the conclusions drawn by Rutherford from his

α

-ray scattering experiment.

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 8

In what way was the Rutherford's atomic model different from that of Thomson's atomic model?

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 4 - Structure of Atom>EXERCISE 4A>Q 1

The ratio of the radii of hydrogen atom and its nucleus is ~10^5. Assuming the atom and the nucleus to be spherical,
(i) what will be the ratio of their sizes?
(ii) If atom is represented by planet earth R_e=6.4×10⁶ m, estimate the size of the nucleus.