11.Which shows the order of decreasing atomic size? a. Si, Al, Mg, Na
b. I, Br, Cl, F
c. Be, Mg, Ca, Sr
d. C, P, Se, I

Which of the following is not a characteristic of a hydrogen bond? 1. it is responsible for the unusual physical properties of water. 2. it is weaker than a covalent bond. 3. it is stronger than other dipole-dipole interactions. 4. it can occur when hydrogen is covalently bound to very electronegative elements liks f, cl, br and i.