An example of a physical change
is liquid water turning into vapor. Physical change is that it may involve a
change in phase but does not involve a change in molecular structure.
In the Bohr's Model of the atom, the protons are located in the nucleus. The electrons move around the nucleus. I hope this helps in some way. (:
Rare earth metals are a group of 17 elements - lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground
