What is the mass of 5.05×1021 platinum atoms?

1.6 gram

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.

To calculate the moles, we use the equation:

1 mole of Platinum weighs 195 g

 of Platinum weigh =

Thus mass of platinum atoms is 1.6 gram.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;