Radon is a radioactive gas with half-life 56 s.For health reasons,the maximum permissible level of radon in air in a building is set a t 1 radon atom for every `.15xx10^(21)` molecules of air 1 mol of air in the building is contained in 0.024 `m^3`.Calculate ,for this building
the number of molecules for air in `1.0 m^3`.

Radon is a radioactive gas with half-life 56 s.For health reasons,the maximum permissible level of radon in air in a building is set a t 1 radon atom for every .15xx10^(21) molecules of air 1 mol of air in the building is contained in 0.024 m^3 .Calculate ,for this building the maximum permissible number of radon atom in 1.0 m^3 of air

Light travels from air to water of refractive index 1.33. calculate the speed of light in water, if speed of light in air is 3.0xx10^8 m/s

Air entering the lungs ends up in tiny sacs called alveoli.From the alveoli, the oxygen diffuses into the blood. The average radius of the alveoli is 0.0050 cm and the air inside contains 14 per cent oxygen. Assuming that the pressure in the alveoli is 1.0 atm and the temperature is 37^(@)C , calculate the number of oxygen molecules in one of the alveoli.

Velocity of light in a liquid is 1.5 xx 10^8 ms^(-1) and in air,it is 3xx10^8 m s^(-1) .If a ray of light passes from this liquid to air ,calculate the value of critical angle.

The rate of a first order reaction is : 1.5 xx 10^-2 mol L^-1 mi n^-1 at 0.5 M concentration of the reactant. The half life of the reaction is :

A plane is in level flight at constant speed and each of its two wings has an area of 25 m^2 . If the speed of the air is 180 km//h over the lower wing and 234 km//h over the upper wing surface, determine the plane’s mass. (Take air density to be 1 kg m^-3 )

Two equal charges placed in air separated by a distance 3 m repel each other with force 0.1 g f. Calculate the magnitude of either of the charges.

Dielectric strength of air is 3xx10^6 V m^-1 . If electric potential on a sphere can be 9xx10^6V , then find the minimum radius of the sphere.

Light enters from air to diamond having refractive index 2.4. what is the speed of light in diamond ? Given speed of light in vacuum =3xx10^8 m s^-1 .