Answer:
-2
Explanation:
7 x 1 - 2 x 1 + 1 x 1 + 3C = 0 (no charge)
6 + 3C = 0
C = -2
<span>Energy is transferred through the separate trophic levels of a food chain or web by feeding.The first trophic level (producers) is that of plants which are examples of autotrophs – they make their own food. Photosynthesis occurs when the plants use solar energy and convert it into chemical energy so it can be stored in a carbon compound. Once this has happened the energy can be taken up by the primary consumers – these are in the second trophic level (herbivores and omnivores). Secondary consumers also need to gain energy in some way, and this is by eating the primary consumers that have gained energy from the producers, this means that the second trophic level has successfully transferred energy into the third level containing omnivores and carnivores. A succession in energy transferral means that a food web or food chain has a tertiary and/or quaternary trophic level which can contain carnivores and omnivores which are plant and animal eaters (this includes humans).This transfer in energy is fairly efficient for the organisms involved as around 10% of light energy that is converted into chemical energy through photosynthesis is transferred through the trophic levels, the rest is lost in respiration, as heat, faeces and urine. Not all of the energy can be passed along a food web or chain as it must be used in other things too, so it cannot be 100% efficient.</span>
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.
So, we calculate how many molecules there are in a drop of water, which we determined contains 0.002775 moles: molecules in a drop of water = (6.022 x 1023 molecules/mole) x 0.002275 moles. molecules in a drop of water = 1.67 x 1021 water molecules.
"B. purple" is the correct answer.
