Answer:
680
Explanation:
When the P680 special pair of photosystem II absorbs energy, it enters an excited (high-energy) state. Excited P680 is a good electron donor and can transfer its excited electron to the primary electron acceptor, pheophytin.
WATER
Solids will usually sink when placed in their own liquids with the exception of water
Explanation:
Ice (the solid form of water) floats on water that is cooler than 4 degrees centigrade. This is unlike any other material and this phenomenon has been referred to as the ‘water anomaly’.
Most substances will sink in their own liquid because the solid form is denser than the amount of their own liquid that they displace when immersed. This is because the particles in the solid are closely packed together hence there are more particles per volume than in the liquid form.
Water however, expands at temperatures below 4 degrees and hence ice is less dense than water at 4 degrees and below. The particles in ice are farther apart than particles of water at 4 degrees and below. There is, therefore, more particles per volume in the liquid form of water than in ice – making ice less dense.
Learn More:
For more on 'water anomaly' check out;
brainly.com/question/871737
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because they are both eukaryotic cells
Answer:
Explanation:
friction between two rock surfaces grinding away minerals.
