91Ó°ÊÓ

The mass of a substance made up of an equal number of fundamental units is defined as a mole.

a)

i) The molar mass of the green (left) material is larger because there are fewer atoms in the same mass (5 green atoms vs. 6 yellow atoms).

ii) The molar mass of the blue (right) substance is larger because there are fewer atoms in the same mass (3 blue atoms vs. 6 red atoms).

iii) The orange (left) material has a higher molar mass since the mass of the same number of atoms is greater.

iv) The molar mass of the grey (left) substance is larger because there are fewer atoms in the same mass.

b)

i) The yellow (right) material contains more atoms per gram since its molar mass is lower.

ii) The red (left) substance has more atoms per gram than the blue (right) substance because the red substance has a lower molar mass.

iii) The purple (right) material contains more atoms per gram due to its lower molar mass.

iv) The red (right) substance has more atomsper gram because the molar mass of the red substance is less.

c)

i) Due to its larger molar mass, the grey (left) material has fewer atoms per gram.

ii) The blue (right) substance has fewer atoms per gram because the blue substance's molar mass is greater.

iii) Due to its larger molar mass, the orange (left) material has fewer atoms per gram.

iv) Because the blue substance has a higher molar mass, the grey (left) substance has fewer atoms per gram

d)

Every material has the same amount of atoms per mole, according to Avogadro's constant.