Because of the fossils found in these sedimentary layers, we could infer that a) land plants are older than land animals. b) vertebrates and invertebrates lived together. c) invertebrates lived on earth before vertebrates. d) land animals lived on earth before ocean dwellers.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called

option d : from a warmer substance to a cooler substance

according to second law of thermodynamic, heat flows from higher to lower temperature region. heat is the transfer of energy from an object at higher temperature to an object at a lower temperature. so energy flows from warmer to colder objects.