What is the half life of an isotope that is 75% decayed after 16 days?

Water's surface tension and heat storage capacity are accounted for by its a) orbitals b) weight c) hydrogen bonds d) mass e) size

Which reason best explains why metals are malleable? a)because they have delocalized electrons b)because they have localized electrons c)because they have ionic bonds d)because they have rigid bonds

My plate recommends that of your nutritional intake comes from fruits and vegetables. a. 30% b. 50% c. 20% d. 40%