Explain what is meant by the Avogadro constant.
Argon-40 
may be assumed to be an ideal gas. A mass of 
of argon-40 has a volume of 
at a temperature of 
. Determine, for this mass of argon-40 gas,
the amount, in mol,
the pressure,
the root-mean-square (r.m.s.) speed of an argon atom.
