ILL GIVE BRAINLIST PLS In which circuit does charge reverse direction many times per second? A. A DC circuit
B. A combined circuit
C. A parallel circuit D. An AC circuit

Hydrogen and helium are both members of?

It is really hard for me right know

Aparticle of mass m is placed in a one-dimensional box of length l. the box is so small that the particle’s motion is relativistic, so that e p2/2m is not valid. (a) derive an expression for the energy levels of the particle using the relativistic energy–momentum relation and the quantization of momentum that derives from connement. (b) if the particle is an electron in a box of length l 1.00 1012 m, nd its lowest possible kinetic energy. by what percent is the nonrelativistic formula for the energy in error?