Answer:
The element argon is in column 8A and is a noble gas. Nobles gases are completely stable because their outershell is filled with all eight electrons. Argon has eight valence electrons.
The answer should be B - Nitrogen Dioxide.
The answer is: the mass of 6.02 x 1023 representative particles of the element.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, molar mas of ammonia is 17.031 g/mol.
M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.
M(NH₃) = 14.007 + 3 · 1.008 · g/mol.
M(NH₃) = 17.031 g/mol.
The molar mass (M) is the mass of a given substance (in this example ammonia) divided by the amount of substance.