When you are charging the phone, it will often light itself up to indicate that the charge is complete. Some phones light up as a reminder of missed text messages or phone calls.
light
Filament of light bulbs are made up of Tungsten.
white
white
it has power
Photons
If your cell phone won't light up, there is something wrong with the inner screen mechanisms. You will need to take it to your provider's repair department.
Granite is the light-colored rock that makes up most of Earth's continental crust.
I am guessing that the products made in the cellphone light it up.
Photon
The fillement inside the bulb makes it light up. It acts a ressistor and only lets a small bit of electricity through, therefor pressurising the energy which makes it hot and makes it glow.