<span>The rare earth elements include the lanthanide series, scandium and yttrium. They are a set of seventeen chemical elements in the periodic table. They really are not that rare but they occur together in nature and are hard to separate from one another.</span>
1. In 1687 following 18 months of intense and effectively nonstop work
2.Hooke
3.Halley
4. Halley urged newton to write Principia mathematica and when the Royal society declined to pay the cost of publishing Halley paid for it out of his own pocket
5.Through using a telescope Galileo Galilei was able to prove the theories of sciences Isaac newton
6. He believe that the speed of an object motion is proportional to the force being applied and inversely proportional to the density of the medium he reason that the object moving in a void would move in definitely fast and thus any and all objects
7. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force
8.gottfried wilhelm von leibniz
Answer:
Chlorine
Explanation:
The P usually stands for Protons, and that is usually the element number. (chlorine is 17) N is for neutron
The answer to this is 22, confirmed by gradpoint
