Do the number of protons in an atom of an element always equals its atomic weight.

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

What is the volume of the fluid in the graduated cylinder with accuracy and measured to the correct degree of precision? 41.2 ml 42.0 ml 41.23 ml 41.89 ml

The peak wavelength for the blackbody curve of a star is in the uv range. assuming the radiation from this star can reach earth, would you be able to see it?