On the periodic table, elements are arranged according to their mass numbers. truefalse

Ineed pls urgent 1-20 in order and fully detail step my step.

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5

Temperature is defined as a. the equivalent of heat. b. a measure of the average kinetic energy of the individual atoms or molecules composing a substance. c. how hot or cold it is. d. the total kinetic energy of the atoms or molecules composing a substance. e. none of the above is correct.