Using the Periodic Table above that means any compound that contains an element shown in orange will contain ionic (electrovalent) bonds. Compounds that form between two non-metals (or between non-metals and metalloids) will contain covalent bonds. Using the Periodic Table above that means any compound that contains element shown in yellow or green will contain covalent bonds.
Porpoises are a group of fully aquatic marine mammals, that are sometimes referred to as mereswine, all of which are classified under the family Phocoenidae, parvorder Odontoceti (toothed whales). There are 8 extant species of porpoise.
There are almost forty different species of dolphins with the killer whale being the largest. The bottlenose dolphin is the species of Flipper fame that we are most familiar with, and the species that is regularly referred to as simply dolphin. The term dolphin is not synonymous with porpoise. Porpoises are six species within the dolphin family differentiated by their flat teeth. So, simply put, all porpoises are dolphins, but not all dolphins are porpoises. The bottlenose is not a porpoise. Dolphins live in groups of 5 to 15 individuals called pods.