That whales have pelvic bones is taken as evidence that A) they probably evolved from fish. B) ancestral whales had legs. C) whales should have legs. D) having a pelvis is advantageous. E) whales did not evolve by natural selection

How many moles of NaCl are in 135 g NaCl?

A compound containing only carbon, hydrogen, and oxygen is subjected to elemental analysis.  Upon complete combustion, a 0.7916-g sample of the compound produced 1.581 g of CO2 and 0.6474 g of H2O.  What is the empirical formula of a compound?

What is true of natural selection? A) Natural selection is a random process. B) Natural selection creates beneficial mutations. C) The only way to eliminate harmful mutations is through natural selection. D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations. E) Mutations occur when directed by the good of the species; natural selection edits out harmful mutations and causes populations to adapt to the beneficial mutations.

Matter is everything that has and occupy . 

What coefficient has to be placed in front of H2O to correctly balance following equation? Remember that entire equation has to be balanced. B2O3(s) + HF(l) → BF3(g) + H2O(l)

What is the mass in grams of one molecule of propene, C3H6?

Which of the following is the lowest temperature? TK = TC + 273 TF = (1.8 x TC) + 32 TC = (TF – 32) / 1.8

A 2.34 g sample of an element contains 2.71×1022 atoms. What is the element symbol?

Iodine pentafluoride reacts slowly with glass and violently with water. Determine its molecular mass.