<span>Correct
answer is 1 - one mole of
NO2</span> . <span> Gram formula mass can be defined as the mass
of 1 mole (6.022 x 10</span>²³ particles<span>) of compound in grams. This is similar to molar mass. Gram formula
mass is also calculated by adding the total mass of each element present in the
given formula. </span>
Elements in the same group on the periodic table have the same number of valence electrons. The "groups" are the column (or rows). groups are vertically and periods are horizontally.
