A battery lighting a bulb is an example of _ energy converting to _ energy.

Electric energy converting into light and heat energy.

So, for the first blank electric, and the second blank the better answer is light.

The power source is electrical (whether the light is plugged in or has a battery)

the light bulb converts the electricity to light and heat.

in a fluorescent bulb, it is different, but the electricity is again converted to light, very little heat, though.