f it is solid iron, use the density to get the mass. D x V = mass
Use the mass to find the moles of Fe. Mass/atomic mass = moles
Moles x Avogadro's number will give you the particles, assuming that you mean atoms.
Answer:
The lowest temperature at which a substance melts
Explanation:
Answer:
The ionization energy (in kJ/mol) of the helium ion is 21,004.73 kJ/mol .
Explanation:

Z = atomic mass
n = principal quantum number
Energy of the electron in n=1,

Energy of the electron in n = ∞

Ionization energy of the
ion:


To convert in into kj/mol multiply it with 

Answer:
a compound
Explanation:
A molecule with multiple atoms is compound like water it's made up of 1 oxygen and two hydrogen.
Answer: Natural selection.
Explanation:
The natural selection is the process by which the organism that best suits the characters will survive and the organism which cannot adapt the changes will die.
The predators feed on their prey and the organism which hides easily in the environment due to its color is safe and the animals that cannot camouflage will die.
This is natural selection that more favored character is carried out over generations and other that cannot survive die.