Identify the phase change described by the following equations. a. C18H38(s) → C18H38(l)

b. CO2(g) → CO2(s)

c. NH3(l) → NH3(g)

Perform the following mathematical operations and report the answer to the appropriate number of significant figures 5.87998 + 3.100

Which element in the third period would you expect to have the larger atomic radius, sodium (na) or sulfur (s)? a. sodium, because it has a higher effective nuclear charge attracting electrons in fewer energy levels. b. sodium, because it has fewer protons attracting electrons in the same energy levels. c. sulfur, because it has more protons attracting electrons in more energy levels. d. sulfur, because it has a higher effective nuclear charge attracting electrons in the same energy levels.

  the mississippians were considered to be  horticulturalists, which means they were