Answer:
The correct answer is electrons.
Explanation:
The electrons refer to the negatively charged constituents, which are arranged in the orbits around the nucleus of an atom. It determines all the chemical and physical characteristics of an atom except the radioactivity and mass. It is a stable subatomic particle witnessed in all the atoms and functioning as the chief carrier of electricity in solids.
Answer:
1. 
2. 
Explanation:
Hello,
1. In this case, since the volume of the rock is obtained via the difference between the volume of the cylinder with the water and the rock and the volume of the cylinder with the water only:

Thus, the density turns out:

2. In this case, given the density and mass of aluminum we can compute its volume as follows:

Moreover, as the volume is also defined in terms of width, height and length:

The height is computed to be:

Best regards.
Answer:
They need to use energy from other tress to survive so that they can do basic functions, like absorbing nutrients from the ground, and growing back leaves. They don't have chlorophyll, so they need that energy to do the functions I mentioned above.
Explanation: Hope this helps!