Which statement describes an event from the light-dependent stage of photosynthesis? 1: protons (h+) are moved against their concentration gradient. 2: water molecules are split. 3: carbon dioxide is consumed. 4: atp and nadph are produced.

The correct answer is option 4, that is, ATP and NADPH are produced.  

The light-dependent reactions refer to an array of biochemical reactions in the process of photosynthesis, which need light energy that is captivated by the light-absorbing pigments like chlorophyll. The light-dependent reactions occur in the thylakoid membranes of the chloroplast.  

The light-dependent reactions use energy in the form of light to produce two molecules required for the next phase of photosynthesis, that is, the energy storage molecule ATP and the reduced electron carrier NADPH.  

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.