Which pair of elements would most likely bond to form a covalently bonded compound?

If you are told to get 100 ml of stock solution to use to prepare smaller size sample for an experiment, which piece of glassware would you use?

What is the difference between covalent bonds and ionic bonds? covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms. covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms.

How does science use models to gain a better understanding of concepts?