Please help with number 7 thank you! 30 points

Which one of the following bonds would you expect to be the most polar? a) b–h b) n–h c) p–h d) al–h e) c–h

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o

Why are enzymes important to cells? they bring about chemical reactions. they provide structural support. they form the two layers of membranes. they store large quantities of energy.