What is the percent composition of compound that has a total mass of 63.9 g that contains 51.0 g cu and 12.9 g o?

Which uses electromagnetic radiation to discover the properties and composition of bodies in space? space probe space station space shuttle space observatory

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

2. you__turn left on a red light if you are in the left-most lane of a one-way street, you're turning into the left-most lane of a one-way street, and no nearby sign prohibits the turn.