NCERT Solutions for Chapter: Air Around us, Exercise 1: Exercise

Identify the layers of atmosphere as per the activities mentioned and arrange them in a sequence.

Burning up of meteorites, flying of aeroplanes, reflection of radio waves, absorption of harmful ionising radiations and occurrence of most of the weather phenomena.

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Ionosphere
5. Magnetosphere

Arrange the following steps involved in the preparation of oxygen from ${\mathrm{KClO}}_3$ in a proper order.

1. Content of the test tube is heated
2. 2. A mixture of finely ground ${\mathrm{KClO}}_3$ and ${\mathrm{MnO}}_2$ is taken in a test tube.
3. The open end of the test tube is plugged with cotton.
4. Delivery tube is taken out.
5. The test tube is fixed in a slanting position.
6. Bunsen burner is put off.
7. Oxygen is collected by downward displacement of water.

The description of the different layers of the atmosphere is given below. Arrange them in the increasing order of their altitude.

1. the layer of atmosphere in which the number of molecules is less, but they are sufficient to burn the meteorites
2. the layer in which the temperature increases with attitude
3. the layer with the least number of particles
4. the convection current of air plays a significant role in this layer 

Air is a homogeneous mixture of gases which also contains argon and nitrogen which are used for filling electric bulbs. But air is not filled in electric bulbs because:

Which of the following reactions is associated with the formation of shining white globules?

Which of the following reactions is associated with the formation of a mirror-like surface near the cooler part of the test tube?

You are asked to prepare oxygen from air after eliminating the impurities in the order, i.e., at first dust particles, then water vapour and ${\mathrm{CO}}_2$ at the end. Based on the given instruction arrange the processes given below in a sequence:

1. passing the sample of air through concentrated NaOH
2. repeated compression followed by sudden expansion
3. fractional distillation of liquefied air
4. passing the air through electrostatic precipitator
5. passing the air through anhydrous ${\mathrm{CaCl}}_2$ 

$\mathrm{X}$ and $\mathrm{Y}$ are gases at room temperature. $\mathrm{X}$ is less reactive and is used to preserve food material, while $\mathrm{Y}$ is required for combustion. Metal $\mathrm{M}$ gets corroded when it combines with $\mathrm{Y}$ in the presence of $\mathrm{Z}$. An atom of $\mathrm{M}$ possesses $14$ electrons in the second last shell and $\mathrm{N}$ is the last shell. Identify $\mathrm{X}, \mathrm{Y}, \mathrm{Z}$ and $\mathrm{M}$.