Which type of radiation travels at the speed of light and penetrates matter easily?

a beta particles
b radionuclides
c alpha particles
d gamma rays

What happens in a global convection cell

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?