A scientist has 1.00 kilogram of pure calcium carbonate solid. She measures a property Z of the calcium carbonate, and finds that 1.00 kilogram measures z units. She then separates a 10-gram sample from the calcium carbonate and measures property Z of the smaller sample. She finds that the smaller sample also measures z units. Which of the following best describes property Z? A.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both

Pastoral farming is best described as a. a method of raising livestock and moving herds b. an african method of agriculture c. a method of cultivating crops on poor soils d. a common method of desert farming select the best answer from the choices provided a b c d