Acandle burns 1.2 m away from a lens with a focal length of 0.4 m. how far away from the lens will an image form?

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

Positive ions differ from neutral atoms in that

When flexing to a reflective style, one should be specific, brief and to the point, and maintain a fast and decisive pace?