Please help with energy

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.

A10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. which one has the greater buoyant force on it? explain. b - the aluminum a) both have the same buoyant force. b) the aluminum c) the lead d) it cannot be determined without knowing their volumes.

Anumber of conditions are required for a population to be in hardy-weinberg equilibrium. which of the following are correct descriptions of the conditions that must be met? check all that apply. a. no mutations b. random mating c. small population d. migration or gene flow e. occurrence of mutations f. no natural selection