List of practice Questions

Give comparison between the following: 
  1. C3 and C4 pathways 
  2. Cyclic and non-cyclic photophosphorylation 
  3. Anatomy of leaf in C3 and C4 plants
What is meant by power of accommodation of the eye?
Gravitational force on the surface of the moon is only \(\frac{1}6\) as strong as gravitational force on the earth. What is the weight in newtons of a 10 kg object on the moon and on the earth?
Why will a sheet of paper fall slower than one that is crumpled into a ball?
Amit buys few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets him at the equator. Will the friend agree with the weight of gold bought? If not, why? [Hint: The value of g is greater at the poles than at the equator.]
What do we call the gravitational force between the earth and an object?
What is the acceleration of free fall?
What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?
The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?

What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 × \(10^{24}\) kg and radius of the earth is 6.4 × \(10^6\) m.)

How does the force of gravitation between two objects change when the distance between them is reduced to half?
Complete the following table.
Atomic NumberMass NumberNumber of NeutronsNumber of ProtonsNumber of ElectronsNumber of the Atomic Species

9

-

10

-

-

-

16

32

-

-

-

Sulphur

-

24

-

12

-

-

-

2

-

1

-

-

-

1

0

1

0

-

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

Number of valence electrons in \(Cl^–\) ion are:

Isotopes of an element have
Rutherford’s alpha-particle scattering experiment was responsible for the discovery of
For the following statements, write T for True and F for False.
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
(c) The mass of an electron is about \(\frac1{ 2000}\) times that of proton.
(d) An isotope of iodine is used for making tincture iodine, which is used as a medicine.
Composition of the nuclei of two atomic species X and Y are given as under 
 XY
Protons 66
Neutrons66

Give the mass numbers of X and Y. What is the relation between the two species?
If Z=3, what would be the valency of the element? Also, name the element.

The average atomic mass of a sample of an element \(X\) is 16.2u. What are the percentages of isotopes \(^{16}X_8\) and \(^{18}X_8\) in the sample?

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

\(Na^+\) has completely filled K and L shells. Explain
Compare the properties of electrons, protons and neutrons.
Explain with examples
(i) Atomic number,
(ii) Mass number,
(iii) Isotopes
(iv) Isobars.
Give any two uses of isotopes.
Describe Bohr’s model of the atom.