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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.

How many atoms does one mole of aluminum contain?

A 5 ft 7 in track athlete weighs 110 pounds. What is her height in cm and her weight in kilograms? (2.54 cm = 1 inch; 454 g = 1 pound)

Identify the entities that will correctly complete the flow chart.   I. II. I. Pure substance Mixture II. Element Atoms III. Mixture Solutions IV. Mass Mixture V. Mixture Atoms

The Cl− ion contains _____ protons and _____ electrons.