How many photons are produced in a laser pulse of 0.593 J at 671 nm?

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

The pressure in a fluid is affected by which characteristics of that fluid

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.