Calculate the pressure in atmospheres of 0.5 mol of helium ( he) at 20°c & occupying 2.50 l.

4.811 atm.

Explanation:

where, P is the pressure of the gas in atm (P = ?? atm).

V is the volume of the gas in L (V = 2.5 L).

n is the no. of moles of the gas in mol (n = 0.5 mol).

R  is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (T = 20°C + 273 = 293 K).

∴ P = nRT/V = (0.5 mol)(0.0821 L.atm/mol.K)(293 K)/(2.5 L) = 4.811 atm.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.