Explanation:
An equation that consists of same number of atoms on both reactant and product side is known as a balanced chemical equation.
For example, 
Number of atoms on reactant side are as follows.
C = 7
H = 6
O = 3
Number of atoms on product side are as follows.
C = 1
H = 2
O = 3
Therefore, to balance this chemical equation we multiply 
by 8 on reactant side. Whereas we multiply 
by 7 and 
by 3 on product side.
Therefore, the balanced chemical equation will be as follows.
Answer:
b I'm sorry if its not true
The mass number represents the summation of the number of protons and the number of neutrons in the nucleus of an atom.
We are given that the mass number is 64 and that the number of neutrons is 35. Therefore:
number of protons = 64 - 35 = 29 protons
In ground state, number of protons in an atom is equal to the number of electrons. Therefore,
number of electrons = 29 electron
Using the periodic table, we will find that the element that has 29 electrons in ground state is copper.
The nuclide symbol of copper is shown in the attached image.
1 mol --------- 6.02x10²³ atoms
6.3 moles ---- ??
atoms = 6.3 * 6.02x10²³
= 3.7926x10²⁴ atoms
hope this helps!
