What element has 4 hydrogen, 1 Carbon, 2 nitrogen and oxygen???

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

How do i complete this electrolysis of water lab? i’m at home, so i don’t have the materials, and the lab didn’t properly work and was incomplete at school.

Acompound has a molar mass of 92.02 grams/mole, and its percent composition is 30.4% nitrogen (n) and 69.6% oxygen (o). what is its molecular formula? a. n2o4 b. no2 c. n2o d. n4o2