I think the answer is 4) All of the above!! :)
11m if you add 6+5 you get 11 but of course you need the “m” in the mix so 11m but correct me if I’m wrong.
Explanation:
a) Density is the amount of mass in a specific amount of volume
b) Some substances are less dense than water so will float and vice versa
c) The wooden plank has less density than water due to having larger volume and vice versa with the wooden block since volume and density are inversely proportional
II) (a) They are all metals
(b) water -> Compound
oxygen -> Element
Gold-> Element
Salt-> Compound
I would say the atmosphere because air and oxygen are essential for human life however it is debatable. You should check out this prezi and judge for yourself which sphere is effected the most from forest fires based on the descriptions on how a forest fire effects all four spheres.
https://prezi.com/m/50ogw-qsyoxc/the-four-spheres/
