How can you tell that a white powder is salt without tasting it

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

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?

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?