What is the molar mass of oxygen, o2? (round to four significant figures only.)

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number of particles.

1 mole of weighs= 32.0 g

Significant digits are each of the digits of a number that are used to express a number to the required degree of accuracy, starting from the first non-zero digit with exponents raised to the power of 10.

The number is written in scientific notation as   contains 4 significant digits.

Thus 32 can be expressed as   contains 4 significant digits.