Any observation must be measurable as well as...

There is one girl i like and i don't know how to tell her that, i have a feeling she knows but if she doesn't i don't want to make a fool out of myself how is one way to boost my confidence on asking her out

If one fission reaction of a uranium-235 atom produced two neutrons, how many neutrons would be released if the chain reaction occurred three more times?

The same side of the moon always faces earth because the