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Chemistry

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2. Solve the problem to the correct # of significant figures with rounding:

1. 0.987 + 24.8352 + 4.32 = _____________
2. 9.9209 x 0.000642  = _______________

3.  Convert 17.23  mol Ag to  atoms Ag

4.  Density Calculate the volume of a sample of ethanol if its density is 0.789 g/mLand has a mass of 6.26 g?

5. Atoms and Ions

a. Determine # of electrons, protons, and neutrons.

                        Protons            Electron          Neutrons              Z                A

Os - 188          _______          ______            _______          ______       ________

         ______              ______            ________        _______     ­­­________

⁵²Mn³⁺           ______              ______            ________        _______     ­­­________

            b. Is Co²⁺ a cation or anion? _______________________

                        p = ______ e^- = ______

6.  Periodic Table. Match the element with the class or group.

1. Ar ____                                                     A. Halogen
2. U _____                                                    B. Alkaline earth metal
3. Sb _____                                                   C. Noble gas
4. Br ____                                                     D. Metal
5. K   ____                                                    E. Metalloid
6. Be ____                                                     F. Alkali metal
7. P   ____                                                     G. Transition metal
8. Fe  ____                                                    H. Nonmetal
9. 7.  Grams and Moles

a. Convert 11.3 g Ca to mol Ca

b. Convert 0.4218mol Cd to g Cd

8.  Classification of matter.

1. Would you describe the observations as chemical or physical changes?
2. Sugar is soluble in water  _______________
3. Water boils at 100 ^oC ____________________
4. Ice is less dense than water.________________________
5. Hydrogen explodes when ignited in air _______________________
6. Homogeneous or heterogeneous mixtures:
7. Salad dressing  _________________________________
8. Apple juice ___________________________________
9. Brass metal ___________________________________
10. Element or compound:
11. Sulfuric acid (H₂SO₄) __________________________
12. Titanium (Ti) ________________________________

9.  History of the Atom

a. Which was the first particle (proton, neutron, or electron) to be discovered ?     Electron

b. Match the instrument to what it was used to discover:        Electron    or    Proton

Oil drop experiment   ___________

Cathode ray tube    ____________                   

Gold Foil experiment ___________  

                          c.  Match the scientist to the particle he worked with:  Proton or Electron or Neutron

Rutherford ___________

       Chadwick  ___________

Thomson ___________

Millikan ____________  

d. Write the scientist with the instrument he used:   Millikan, Thomson, Rutherford

Oil drop ____________________

Gold foil ____________________

Cathode ray _________________

1. Who found the:  Chadwick, Rutherford, Thomson, or Millikan

Proton and model of atom _______________________________

Neutron _______________________________

Charge of the electron _______________________

Mass to charge ratio of the electron ________________________

Multiple Choice.  You can just write # and then letter answer

1) A substance that can't be chemically broken down into simpler substances is

A) a homogeneous mixture.

B) an element.

C) a heterogeneous mixture.

D) a compound.

E) an electron.

2) A physical change

A) occurs when iron rusts.

B) occurs when sugar is heated into caramel.

C) occurs when glucose is converted into energy within your cells.

D) occurs when water is evaporated.

E) occurs when propane is burned for heat

3) Which of the following are examples of a chemical change?

A) coffee brewing

B) water freezing

C) leaves turning color in the fall

D) salt dissolves in water

E) None of the above are chemical changes.

4) Isotopes differ in the number of ________.

A) beta particles

B) protons

C) electrons

D) neutrons

5) In a chemical reaction, matter is neither created or destroyed.  Which law does this refer to?

A) Law of Definite Proportions

B) Law of the Conservation of Mass

C) Law of Modern Atomic Theory

D) Law of Multiple Proportions

E) First Law of Thermodynamics

6) Ions differ in the number of

A) electrons.

B) neutrons.

C) protons.

D) neutrons and protons.

E) electrons and protons.

7) Predict the charge that an ion formed from nitrogen would have.

A) 1-

B) 6+

C) 3-

D) 4+

E) 2-

8) Give the number of protons in Na+1.

A) 10

B) 13

C) 9

D) 11

E) 12