Mole=number of molecules/6.02x10²³
mole=2
number of molecules= 2x6.02x10²³
number of molecules=12.04x10²³
Water can't cool at a single temperature. It must start at a higher temperature, and drop to a lower temperature in order to cool. Unless we know the other temperature, there is no way to calculate the amount of thermal energy released.
Answer:
Rock A because after physical weather and chemical weathering it more likely for Rock A to experience more chemical weathering.
Explanation: Weathering: This is a geological term used to describe the various processes and Activities involved in the breaking down of rocks either through physical,mechanical,chemical etc actions into smaller particles.
ROCK A WILL HAVE MORE CHEMICAL WEATHERING BECAUSE THE PHYSICAL WEATHERING MUST HAVE BROKEN DOWN THE PARTICLES FOR EASY WATER AND OTHER SUBSTANCE NEEDED FOR EASIER CHEMICAL REACTION OR WEATHERING.
Answer:
The molar mass of the unknown gas is 
Explanation:
Let assume that the gas is O2 gas
O2 gas is to effuse through a porous barrier in time t₁ = 4.98 minutes.
Under the same conditions;
the same number of moles of an unknown gas requires time t₂ = 6.34 minutes to effuse through the same barrier.
From Graham's Law of Diffusion;
Graham's Law of Diffusion states that, at a constant temperature and pressure; the rate of diffusion of a gas is inversely proportional to the square root of its density.
i.e

where K = constant
If we compare the rate o diffusion of two gases;

Since the density of a gas d is proportional to its relative molecular mass M. Then;

Rate is the reciprocal of time ; i.e

Thus; replacing the value of R into the above previous equation;we have:

We can equally say:





