Which wave can be transmitted through empty space

What is lincoln's purpose in writing this speech? question 1 options: to stress the difficulties of war to honor those who died in the war to call for an end to the war to call the country to join a new war

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?