Matter in Our Surroundings — Science STD 9 — Question

Define the term impulse.

Write down the formulae of.
magnesium hydroxide.

Name two indigenous breeds of draught cows.

What is the maximum number of electrons that can go into the N shell of an atom?

Name the principle on which a rocket works.

A piece of chalk can be broken into small particles by hammering but a piece of iron cannot be broken into small particles by hammering. Which characteristic of the particles of matter is illustrated by these observations?

When a ball is thrown vertically upwards, its velocity goes on decreasing. What happens to its potential energy as its velocity becomes zero?

Each beehive consists of thousands of hexagonal thin-walled fragile cells. Name the material which is used to make these cells and mention the significance of the hexagonal shape of the cell.

As the altitude of a body increases, do the weight and mass both vary?