Which of the following conditions remain constant in charles's law?
volume and pressure
density and temperature
pressure and number of moles
temperature and number of moles

Pressure and number of moles.

Explanation:

According to Charles law,

For an ideal gas, volume is directly proportional to temperature at constant pressure for a fixed amount of gas.

V ∝ T

From the law we can say that the two conditions are:

Pressure and number of moles

Explanation:

Charles law states that the volume of a given mass of gas is directly proportional to its absolute temperature provided its pressure remain constant. V = KT

k = V/T

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.