How many atoms of hydrogens are found in 3.21 mol of
C3H8?

1.55 × 10²⁵ atoms of H  

Explanation:

3.21mol C₃H₈ × 8mol H × (6.022×10²³)

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

hope i !