When light energy excites electrons in photosystem ii, where do the electrons to replace them come from?

a. atp
b. photosystem i
c. the light energy
d. split water molecules

Which type of bond forms between water moleculesstrong bondhydrogen bondcovalent bondpolar bond

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

In the diagram below, the northern hemisphere would be in what season at position a a. fall b. winter c. summer d. spring