Previous paper class 9th(Chemistry)

Q No. 2: Short Questions. /30
1) Why does ice floats on water?
2) Differentiate between lone pair and bond pair of electrons.
3) Why HCl has dipole-dipole forces of attraction?
4) Why does a covalent bond become polar?
5) What is octet rule?
6) What is Lewis structure of diagram?
7) What is meant by malleable and ductile property of metals?
8) Give some properties of epoxy adhesives?
9) Briefly explain about standard atmospheric pressure?
10) In which unit blood pressure is measured?
11) Define absolute zero?
12) What is meant by mobility of gases?
13) Why the rate of diffusion of gases is rapid than that of liquids?
14) Convert 1.5 atm to Pascal.
15) Which variables are kept constant in Charles’s law?