Answer:
The height of A is 900
Explanation: Beside A, there is a number which explains what the height is so the answer is A.
Nope, it's a physical change. When ice melts it changes into liquid water, it's still water. Changes in which no new substances are formed are physical changes, hence this is a physical change.
excess hydrogen ions can break chemical bonds
, can change the shape of large complex molecules, rendering them nonfunctional and can disrupt tissue function.
Dihydrogen oxide is the right answer. Dihydrogen oxide is just 2 hydrogen and 1 oxygen which is H2O or water.
Helium,it has an atomic mass of 4,which means total no. of protons and neutrons,so I think you meant 2 protons and an atomic mass of 4
