Answer:
Producers are autotrophs, or organisms that produce their own food. ... They are at the bottom of the food chain because they are eaten by other organisms, and they don't need to eat for energy. Producers make their own food through the process of photosynthesis instead of eating organic matter.
I think that you didn't copy the answers correctly, because 1 and 2 are the same, and 3 and 4 are also the same here.
Anyways, the answer which is correct is that an electron has a charge of -1, and a proton has a charge of +1.
Electrons are negatively charged, whereas protons are positively charged. Neutrons are neutral.
Solubility rules state that group one metals and Nitrates are always soluble. Rubidium is a group one metal, so Rubidium Nitrate, RbNO3, is soluble.
Low-cost energy. Although building nuclear power plants has a high initial cost, it's relatively cheap to produce energy from them and they have low operating costs.
Reliable.
Zero carbon emissions.
Promising future energy supply.
High energy density.
