Answer:
D: lose an electron
Explanation:
when an atom loses an electron it's positively charged and when it gain an electron it is negatively charged
We need to know the relationship between atmospheric pressure and the density of gas particles in an area of increasing pressure.
The relationship is: As air pressure in an area increases, the density of the gas particles in that area increases.
For any gaseous substance, density of gas is directly proportional to pressure of gas.
This can be explained from idial gas edquation:
PV=nRT
PV=
RT [where, w= mass of substance, M=molar mass of substance]
PM=
RT
PM=dRT [where, d=density of thesubstance]
So, for a particular gaseous substance (whose molar mass is known), at particular temperature, pressure is directly related to density of gaseous substance.
Therefore, as air pressure in an area increases, the density of the gas particles in that area increases.
Answer: There are
molecules in 63.00 g of 
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the moles, we use the equation:

1 mole of
contains =
molecules
Thus 3.5 moles of
contains =
molecules.
There are
molecules in 63.00 g of 
D have the same opinion on the contain resisting
1000 liters equal to one cubic meter
so 250 ml is equal to 0.25 liters.
where it is 0.25 m cube