The number of energy levels to which an electron can jump depends on the amount of energy the electron possesses. Each energy level has a specific amount of energy an electron needs to have before it can be in there. So, if an electron doesn't have enough energy to be in that energy level then it won't jump to that higher level.
Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
A decomposition reaction<span> is a type of chemical </span>reaction<span> in which a single compound breaks down into two or more elements or new compounds. These </span>reactions<span> often involve an energy source such as heat, light, or electricity that breaks apart the bonds of compounds. so it is a decomposition reaction because the silver chloride breaks down into silver and chlorine</span>
Given
Mass number of isotope = 63
Number of neutrons = 33
So number of protons = 63 - 33 = 30
Hence atomic number of metal = 30
thus metal is = zinc
now as it is forming cation with 28 electrons it means it has lost two electrons so it must have a dipositive charge
the symbol of metal ion will be
Zn^+2