Its the the number of proteins and neutrons in the atom.
Answer:
Selectively permeable means a membrane allows the passage of some molecules or ions and inhibits the passage of others.
Explanation:
Hope that helps :)
A Fossil Fuel is the highest
b Nuclear goes down during 2005-2015 but solar is the lowest through it all but it seems to increase a little between 2005-2015 so I’m not sure which one but it’s between those two
