Two one-liter containers each contain 10 moles of a gas. the temperature is the same in both containers. container a holds helium (molecular mass = 4 u), and container b holds oxygen (molecular mass = 16 u). which container has the higher pressure and by what factor?

Using the Ideal gas equation,

Here, P is pressure of the gas

V is the volume of the gas,

n is number of moles,

R is universal gas constant, and

T is absolute temperature

As all the factors are the same for helium and oxygen gases except their molecular mass,

So, we can say that pressure exerted by the gases is inversely proportional to their molecular mass. That is,

P₁= Pressure exerted by the helium gas

P₂= Pressure exerted by the oxygen gas

m₁= Molecular mass of helium gas = 4 u

m₂= Molecular mass of oxygen gas = 16 u

The pressure exerted by the helium gas is more than that by oxygen gas by 4 times.

the diagram which shows forces as either balanced = same speed or unbalanced = accelerarting

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.