Assume that a room at sea level was filled with a gas of oxygen molecules O2 in thermal equilibrium at 0 °C. There are 8 protons and 8 neutrons in the nucleus of an oxygen atom O. You may take the masses of the proton and the neutron to be the same, and ignore the mass of the electrons. 1 atm=1.01х105 N/m2 , ℏ=1.05х10-34 J·s , mp=1.67х10-27 kg.
a) What would the (particle) number density be according to the ideal gas law?
b) Compare the number density with the quantum concentration at the same temperature.
c) Is the gas in the classical or quantum regime

i believe the answer would be:

d. violin, clarinet, french horn, and tuba

the closer the planet is to the sun, the larger the gravity

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.  

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =