Here we go, this is from an essay I once wrote, hope it helps.
Answer:
12.7mol Na.
Explanation:
Hello there!
In this case, according to the concept of mole, which stands for the amount of substance, we can recall the concept of Avogadro's number whereby we understand that one mole of any substance contains 6.022x10²³ particles, for the given atoms of sodium, we can calculate the moles as shown below:

Thus, by performing the division we obtain:

Regards!
The answer is yes. A chemical change occurred.
Chemical change is defined as the rearrangement or alteration in the of atoms in one or more substance which result in the formation of a new substance.
In the above, you mixed two clear liquids and the result was a new substance which is a colored solid precipitate at the bottom of the beaker.
This means that changes in the atoms of the two clear liquids occurred leading to the formation of this new solid substance.
This means that chemical change has occurred.
Hope this helps :)
1 and 3 only because metal are easily to loss electron while non metal are difficult to loss electron that's why it called heavy elements.