Hydrogen and oxygen are different elements ...
but when two or more elements combine... it is known as a compound.. hence hydrogen and oxygen together form a compound
The gram-formula mass means that the mass of one mole molecule. Then you just need to calculate the elements together. So the gram-formula mass of (NH4)3PO4 is equals to (14+4)*3+31+16*4= 149g/mol. So the answer is (c)
Answer:
because weight depends on the gravity, gravity decrease s with increasing altitude,hence I have less weight