The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element ?

Two particles are placed at some distance. If the mass of each of the two particles is doubled, keeping the distance between them unchanged, the value of gravitational force between them will be

The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

Which of the following has maximum number of atoms?

The mass of moon is about 0.012 times that of earth and its diameter is about 0.25 times that of earth .The value of G on the moon will be

Which of the following correctly represents 360 g of water?
(i) 2 moles of $H_{2}O$
ii) 20 moles of water.
iii) $6.022\times {10}^{23}$ molecules of water.
iv) $1.2044\times {10}^{25}$ molecules of water.

What is the difference between aerosol and foam?

Which of the following is not a suspension?

Write any three differences between "True solution" and "Suspension"?

A suspension of liquid droplets or fine solid particles in a gas is called :