From my research and own thoughts I think D
Answer:
Jodi is violating two rules; She is not wearing any safety equipment and managed to catch fire to herself. She is also not wearing gloves or safety goggles like the other two. Kimberly is leaving fire unattended, and can cause many accidents and if chemicals come in contact in the wrong way, it could be catastrophic. Kimberly is also carelessly using a fire extinguisher carelessly and chemicals in the can cause accidents.
Explanation:
I hope this helps <3
Answer:
Sodium hydroxide solution.
Explanation:
because it is a strong base. Since carbonic acid is a weak acid, a solution formed resists change in pH on addition hence buffer formed.
ANSWER:
4 a) Specific elements have more than one oxidation state, demonstrating variable valency.
For example, the following transition metals demonstrate varied valence states:
,
,
, etc.
Normal metals such as
also show variable valencies. Certain non-metals are also found to show more than one valence state 
4 b) Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.
For example, Carbon-14 is a naturally occurring radioactive isotope of carbon, having six protons and eight neutrons in the nucleus. However, C-14 does not last forever and there will come a time when it loses its extra neutrons and becomes Carbon-12.
5 a)
→
5 b)
→ 
5 c)
→
(already balanced so don't need to change)
5 d)
→
5 e)
→ 
EXPLANATION (IF NEEDED):
1. Write out how many atoms of each element is on the left (reactant side) and right (product side) of the arrow.
2. Start multiplying each side accordingly to try to get atoms of the elements on both sides equal.
EXAMPLE OF BALANCING: