It means it is an ion. It has lost two protons making it a positive ion.
Nitrogen is crucial to the marine life and it is disappearing because it cannot be assimilated by most organisms in the water.
The size of this engine in cubic meters is
.
<u>Explanation:</u>
As it is stated that engine size can be measured depending upon the amount of air the cylinders displace, it is also stated that the engine of model Pontiac V8 has a size of 316.6 cubic inches. The problem is to convert the size of engine in cubic meters. We know that 1 inch = 0.0254 m.
Then 
As here the size of engine is 316.6 cubic inches, then in metres it will be

Thus, the size of the engine in cubic meters will be
.
The present carbon skeleton in an ether is C-C-C-O-C-C-C because ethers conatins C-O-C as functional group