Crystals can have bonds between their atoms.
ionic
covalent
metallic
all types of

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

What are the dimensions of the cross section that passes through the points a, f, g, and d?

The three classes of rocks are sedimentary, metamorphic, and igneous. how are rocks classified into one of these three groups?