Answer:
Pure Chemistry -- is NOT considered a branch of Chemistry.
Explanation:
Second question is number 4.
Answer:
1 I'm doing this in science class right now I got help yesturday on it! hope this helps
A scientific theory is a well tested explanation of a natural phenomenon.
Answer:
50. 5mol
Explanation:
The mass of Zinc required = 3.30 kg = 3300 grams
The relation between moles and mass is:

Atomic mass of Zinc = 65.38g/mol


The answer to three significant figures will be 50.5 mol
Option 2, Br. I'll go over why all other three options are incorrect.
Option 1 - Krypton is a Noble gas, and so it doesn't need to accept electrons since it has an octet.
Option 3 and 4 - Both Calcium and Barium are alkaline earth metals, and give away electrons, since they only have 2.
-T.B.