Answer: Thats false the Russians were the first
Explanation:
It would be C, because Ionic bonds have to deal with valence electrons ( the outer shell ones)
B3+ is isoelectronic with helium.
Isoelectronicity is the phenomenon whereby two or more molecular entities have the same number of electrons or similar electronic configuration regardless of the nature of the elements that are involved.
In the question given above, helium and B3+ have the same number of electrons. Helium has two electrons. Boron has five electrons but it has given away three of the electrons [that is why it has a charge of +3] and it now has only two left.
A. the moon's gravitational pull on earth causes water to bulge on two sides of the earth
Mole= Molarity. Volume(L) = (25)(2)= 50 moles