Ncert science solutions class 9 Solutions for Chapter 4 structure of the atom

What are the canal rays?

If an atom contains one electron and one proton, will it carry any charge or not?

Draw a sketch of Bohr’s model of an atom with three shells.

Write the distribution of electrons in Carbon and Sodium atoms.

If K and L shells of an atom are full, then what would be the total number of electrons in the atom?

How will you find the valency of chlorine, sulphur and magnesium?

With the help of given Table, find out the mass number of oxygen and sulphur atom.

Table: Composition of Atoms of the First Eighteen Elements with Electron Distribution in Various Shells.

For the symbol H, D and T, tabulate three subatomic particles found in each of them.

Write the electronic configuration of any one pair of isotopes and isobar.

What are the limitations of J.J.Thomson’s model of the atom?

Explain with examples

(i) Atomic number,

(ii) Mass number,

(iii) Isotopes and

(iv) Isobars.

Give any two uses of isotopes.

Na+ has completely filled K and L shells. Explain.

If bromine atom is available in the form of, say, two isotopes _{35}Br^{79} (49.7%) and _{35}Br^{81} (50.3%), calculate the average atomic mass of Bromine atom.

Which one of the following is a correct electronic configuration of Sodium?

(a) 2, 8

(b) 8, 2, 1

(c) 2, 1, 8

(d) 2, 8, 1

Complete the following table.