Typically, the IR energy is absorbed by the glass as heat.
Glass does not block ultraviolet light. You get a sunburn by exposure to excessive ultraviolet light.
Glass is transparent to visible light, meaning that light within the visible spectrum (which includes colors we can see) can pass through it with relatively little absorption or scattering. However, glass is not transparent to certain wavelengths of light outside the visible spectrum. One example is ultraviolet (UV) light. While some types of glass can transmit UV light to varying degrees, many common types of glass, especially ordinary window glass, absorb or block a significant portion of UV radiation. This property is beneficial for protecting indoor spaces from the harmful effects of UV radiation, such as sunburn and fading of interior furnishings. So, while glass may be transparent to visible light, it can be opaque or partially opaque to other wavelengths, such as ultraviolet light.
Ultraviolet is a type of electromagnetic radiation. It has a higher frequency than visible light. It is called ultraviolet because violet light has the highest energy of the colours. UV light has more energy, and hence ultraviolet.
Yes, most types of glass block a significant amount of ultraviolet (UV) light from passing through. However, some special types of glass called "UV-filtering glass" or "low-E glass" are designed to allow some UV light to pass through while blocking the majority of it.
Ultraviolet light, x-rays, and gamma rays carry more energy than visible light. (That's why ultraviolet light does nasty things to skin cells, and x-rays and gamma rays can penetrate solids.)
Ultraviolet radiation is of higher energy than visible light. Ultra-violet suggests that it is above violet in the spectrum, and the colour violet is the uppermost region of visible light.
Ultraviolet light has a greater energy per photon.
Some of it reflects (bounces) back to the source. Some of it is absorbed into the glass, and never heard from again. The rest of it passes through the glass and continues on its way.
Yes, there is some reflected light lost at each interface, which will lower the intensity of the beam. The polarization may be affected too. Depending on the glass there might be a color shift.
Heat
An atom could put off ultraviolet light if it was excited by ultraviolet light at the appropriate energy level. Atoms emit light when they are hit with the exact energy of photon to promote electrons to higher orbitals. The light is emitted as the electron drops back to its ground state.