First off chlorine is not a metal so you can ignore that one.
Sodium and Rubidium are in group 1 of the periodic table and Magnesium is in group 2.
Group one metals are more reactive than group two because it is harder for the group two metals to lose their 2 valence (outer most) electrons.
As you go down group 1 there is an increase in the reactivity this is because as you go down there is an increase in the atomic radius which leads to more shielding. This weakens the electrostatic forces of attraction making it easier to lose the outermost electrons, therefore they are more reactive.
<span>For isotopes of any element, the number of protons remains the same, BUT the number of neutrons changes. Since each of the isotopes listed is phosphorus, All three have 15 protons. (They have 16, 17 and 18 protons respectively.)</span>
A simply because of I'm a pretty good guesser, Hope this helps.
Answer:
A general guideline to determine if oxide is acidic, basic, or amphoteric is to use the periodic table. Typically, metals such as Ba form basic oxides (BaO), while nonmetals such as S form acidic oxides (SO3).
I think the answer is c. two molecules
