What is scientific "law"? A. all experiments appear to "prove" the theory
B. all predicted observations are verified
C. the law is repeatable
D. no exceptions to the law are known
F. all of the above

12. complete each of the following word equations for synthesis reactions. a. sodium + oxygen -> b. magnesium + fluorine -> 13. complete and balance the equations for the decomposition reactions. a. hgo -> [with the triangle heat symbol above the arrow] b. h2o(l) -> [with "electricity" written above the arrow]

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.