How do you know how many electrons there are in each energy level?

How many muscles does it take to smile 17,31,57?

What is the name given to many of the elemnts that have more that one oxidation number?? is it isotopes?

How many standard time zones are there in the world ?

I'm wrighting a report about mercury in fish and I need to know. (:

Nuclear Energy a. Where does radiation come from? What does radioactive decay have to do with its creation? b. Explain whi...

How many atoms is an average person made up of. I know that the Universe contains about 10^80 atoms. Does anyone know how m...

how many faces does a rectangular prism have? And how many vertices

So, I'm not going to get into exactly why I'm asking because it will detract from my actual question. Nonetheless it shouldn'...

How many days does it take for saturn to revolve around the sun?

I Need An Idea For A Science Experiment. I Would Like To Do Something Related To Beauty But I Have No Clue What. Help?