As a mercury atom absorbs a photon of
energy, an electron in the atom changes from
energy level d to energy level e.
determine the energy of the absorbed photon in
electronvolts.

Hydrogen and helium are both members of?

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight

Acapacitor is storing energy of 3 joules with a voltage of 50 volts across its terminals. a second identical capacitor of the same value is storing energy of 1 joule. what is the voltage across the terminals of the second capacitor?