Use the following balanced reaction to solve 1-3: P4 (s) + 6H2 (g) → 4PH3 (g)

1. How many grams of Hydrogen gas (H2) will be needed to react with 20 grams of P4?

1.96g H2

Explanation:

P4 = 123.9g/mol

H2 = 2.02g/mol

* * * = 1.96g H2

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.