1. Indicate the classification for each of the following materials as defined in Section 11.1 in the textbook; (1) fruit cake, (2) the alloy of iron called stainless steel, (3) common table salt, (4) water with lemon juice and sugar added to it, (5) plutonium.

(1) Fruit cake is a heterogeneous mixture since it has a non-uniform appearance and is made up of several different substances combined in a non-chemical way.

(2) Stainless steel is a homogeneous mixture and could be further classified as a solid solution because other metal atoms are dissolved in iron.

(3) Salt (NaCl) is a definite chemical combination of the two elements sodium and chlorine, and so is classified as a compound.

(4) Lemonade is an aqueous solution and in this case is in the liquid phase.

(5) Plutonium can be found in the periodic table (Z = 94) and is classified as an element because all of its atoms have the same number of protons.

2. Give the appropriate name or chemical symbol for each element listed: oxygen, tin, gold, U, Al, and Zn.

Oxygen has the symbol O, tin has the symbol Sn, gold has the symbol Au, U is the chemical symbol for uranium, Al is the symbol for aluminum, and Zn is the symbol for zinc. Note that oxygen is diatomic and so is generally written as O₂ in chemical equations instead of simply O.


3. From the periodic table, find the atomic mass, atomic number, number of protons, and the total number of electrons in an atom of each element listed in question 2 above.

Oxygen: 16.0 u, 8, 8, 8		Tin: 118.7 u, 50, 50, 50
Gold: 197.0 u, 79, 79, 79		U: 238.0 u, 92, 92, 92
Al: 27.0 u, 13, 13, 13		Zn: 65.4 u, 30, 30, 30

4. Identify each element in question 2 above as being either a representative, transition, or inner transition element.

Oxygen is a representative element, tin is a representative element, gold is a transition element, uranium is an inner transition element, aluminum is a representative element, and zinc is a transition element.


5. List the total number of electrons, the number of valence electrons, and the number of occupied electron shells for each element in Period 3 as shown in the periodic table found in the textbook.

Sodium: 11, 1, 3		Magnesium: 12, 2, 3
Aluminum: 13, 3, 3		Silicon: 14, 4, 3
Phosphorus: 15, 5, 3		Sulfur: 16, 6, 3
Chlorine: 17, 7, 3		Argon: 18, 8, 3

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