It's a test
2naoh + h2so4 → na2so4 + h2o
the equation is [balanced/unbalanced], because the number of hydrogen atoms and [oxygen/sodium] atoms is [equal/not equal] in the reactants and in the products.

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.