What does this chemical reaction describe?
water > hydrogen > oxygen

a.) respiration
b.) decomposition of water
c.) combustion of hydrogen fuel
d.) chemical reaction in a battery

Acoil formed by wrapping 80 turns of wire in the shape of a square is positioned in a magnetic field so that the normal to the plane of the coil makes an angle of 28.0° with the direction of the field. when the magnetic field is increased uniformly from 200 µt to 600 µt in 0.400 as, an emf of magnitude 80.0 mv is induced in the coil. what is the total length of the wire?

The total amount of energy contained in an object

Could we see a galaxy that is 20 billion light-years away?