<span>Aluminium is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal. Aluminium is the third most abundant element, and the most abundant metal, in the Earth's crust that is why</span>
Aluminum is a substance because it is a particular type of matter that has particular and unique properties. aluminum is a unique element with a place on the periodic table
H-1 only has 1 proton and 1 electron, so its mass number is 1. H-2 has one more neutron so its mass number is 2 H-3 has one more neutron than H-2 so its mass number will be 3. average atomic mass = 1 x 99% + 2 x 0.8% + 3 x 0.2% =1.012
