For the first one it’s 69 just count the little lines from the side.
The statement that the friend made is not true. most of the mass of the plant is from carbon. the carbon comes from carbon dioxide which is used during photosynthesis. the left over carbon from photosynthesis is used to to help the plant gain mass. there is a process for this which is called cellular respiration
The atoms of hydrogen that are present in 7.63 g of ammonia(NH3)
find the moles of NH3 =mass/molar mass
7.63 g/ 17 g/mol = 0.449 moles
since there is 3 atoms of H in NH3 the moles of H = 0.449 x 3 = 1.347 moles
by use of 1 mole = 6.02 x10^23 atoms
what about 1.347 moles
= 1.347 moles/1 moles x 6.02 x10^23 atoms = 8.11 x10^23 atoms of Hydrogen
I believe the most massive element that is naturally occurring on Earth is uranium (U), which has a nucleus of 92 protons
