posted by Mary on .
Classify the following bonds as ionic, covalent, or neither (O, atomic number 8; F, atomic number 9; Na, atomic number 11; Cl, atomic number 17; U, atomic number 92).
a.) O with F _________
b.) Ca with Cl __________
c.) Na with Na _________
d.) U with Cl __________
First, I do not understand what the atomic number has to do with the type of bonding. Second, I learned that an atom that has only a few electrons in its valence shell will readily give up its electrons to form an ionic bond with an atom that has a mostly full valence shell. Covalent bonds tend to form between elements that both have a strong hold on their electrons. So, I would say the answers should be: a) O with F is covalent since they both have most of their electrons in their valence shells; b) Ca with Cl is ionic since CA only has 2 out of 18 electrons in its valence shell and so would have a weak attraction on them, while Cl has 7 out of 8 electrons and so would have a strong attraction for one of Ca's extra electrons; c) Na with Na would be neither, since each has a weak attraction for electrons; d) U with Cl would be either ionic because U has only 6 out of 32 electrons in its valence shell which would be attracted by the Cl, or neither because they would both hold onto their electrons.
Is this right? Thanks!
I agree with a and b.
I don't agree with c. If Na bonds to Na it will be covalent just as O2, H2, N2, etc, are covalent.
Probably UCl6 is ionic. The electronegativity of U is about 1.4 and Cl is about 3; the difference is about 1.8 and that is close to the 1.9 we usually use for the 50% ionic/covalent character. A more accurate description might be a polar covalent bond for UCl6 but you don't have that as a choice.