Hello!
The center of an atom is called the nucleus; it is comprised of protons and neutrons, collectively known as nucleons. The electrons float around the nucleus in a cloud.
Answer:
A) Protons and neutrons are in the center of the atom, and electrons move around in the cloud.
Hydrogen i suppose is the right one
Answer:
As you cool a matter to absolute zero, their kinetic energy reduces significantly and the molecules slows down and begins to aggregate together. ... As heat is added, the molecules gain more kinetic energy. This shown in their increase motion. When heat is withdrawn, the particles slows down hope this helped
Explanation: This is a reaction of oxidation of 
in the presence of acidified 
. Acidified is a strong oxidizing agent.
To balance out the 
on the reactant side, we write 
on the product side.
Balancing out the following reaction gives us:
Considering that scientific notation has to move the decimal over so there is only one digit in the Tens place, that is the scientific notation.
