Here is back side of worksheet that k just don’t understand please help me

Generally, observed behavior that can be formulated into a statement, sometimes mathematical in nature, is called a(n): a. observation. b. measurement. c. theory. d. natural law. e. experiment.

Pl what kind of reaction is this? nahco3 + h2o → co2 + naoh + h2o -composition -decomposition -single replacement -double replacement im leaning more toward single replacement. if im wrong can you explain whyy?

Match each state of matter with the statement that best describes it.