One mole of water weighs 18 grams. H₂O is composed of 2H= 2 and 1 0=16 adding gives you 18. number of moles= mass/ Relative Molecular Mass
Therefore, mass= Relative Molecular Mass×number of moles
= 18×5 moles
= 90 grams
The branch of chemist is a substance of science and pysical is the land science such as a desert of a forest those are chemist and physical science have a good day :)
C. Electron. It’s a negatively charged particle that orbits around the nucleus. Usually, there are multiple electrons going around the nucleus in different orbitals (the circle around the nucleus in which the electron travels). The mass is much smaller compared to that of a proton or neutron and can be ignored when calculating the mass of an atom.