What is name of first man made element?

Amixture of gaseous sulfur dioxide and oxygen are added to a reaction vessel and heated to 1000 k where they react to form so3(g). if the vessel contains 0.669 atm so2(g), 0.395 atm o2(g), and 0.0851 atm so3(g) after the system has reached equilibrium, what is the equilibrium constant kp for the reaction: 2 so2(g) o2(g) ⇌ 2 so3(g)

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

Why are people not able to scuba dive in the deep part of the ocean