Which type of bond is found between atoms of solid cobalt?
(1) nonpolar covalent (2) polar covalent (3) metallic (4) ionic

The answer is (3) metallic. Cobalt is a transition metal, so it can't be covalent bonds, which bond non-metals, therefore eliminating choice 1 and 2. Ionic bonds are between metals and non metals, but solid cobalt does not have a non metal, eliminating choice 4 as well. Metallic bonds are bonds between metals, therefore the answer is (3) metallic.

29.1-12=17.1the answer is this one