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Choose the answer that best completes each sentence Sólo __ televisión los fines de semana.

Fill in the blank with the correct from of estar: Yo _______   nerviosa por el viaje.

Which of these numbers has four significant figures?

One milliliter is equal to _____.

Calculate the number of moles in a 233-gram sample of barium.

Methane can be decomposed into two simpler substances: hydrogen and carbon. Therefore, methane is a(n) _____.

Which of the following elements is not a nonmetal?

The Ca2+ ion contains _____ protons and _____ electrons.

Which of these elements has seven valence electrons?

1.  Answer the following questions for an atom of sulfur.     A.  The atomic number of sulfur is ________ and sulfur contains _______ protons and ________ electrons.     B.  The electron configuration for sulfur is:          1st energy level = ____ electrons   2nd energy level = ____ electrons 3rd energy level = ____ electrons     C.  An atom of sulfur has ______________ valence electrons.     D.  A particular isotope of sulfur has a mass number of 34.  (34S)           This isotope contains ______ protons,  __________electrons, and __________ neutrons.     E.  Sulfur is a member of the _________ family of elements.     F.  When sulfur forms an ion is will have a _____________ charge.  (negative 1, negative 2, positive 1, positive 2   2.  1 mole of phosphorus has a mass of _____________ g.   3.  How many moles of copper are there in some copper wire weighing 7.75 g?  Show the set up for credit.