7. Circle the letter of the sentences that describe Thomson's model of the atom.
a. An atom is filled with positive matter.
b. An atom is mostly space with a small nucleus.
c. Negative charges are scattered throughout an atom.

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.