A. Releasing a stimulus when hormones increase or decrease I think
Answer:
Water earth fire and rain hurricanes fire tornados etc
Explanation:
There are millions of physical conditions but that's the only ones I could think of.
Answer:
The smallest particle is the electron (option D).
Explanation:
The electron is a subatomic particle, which is part of an atom and has a negative electrical charge.
Electron is a small particle, if compared to protons -electrically positive particles- whose size is about 1800 times bigger. In fact, the electron is the smallest particle inside the atom.
<em> According to this, the other options, </em><u><em>atom</em></u><em>, </em><u><em>nucleus</em></u><em> and </em><u><em>proton</em></u><em> are structures larger than an electron.</em>