Chemistry CCA Study Guide by pengxiang


									Chemistry Q3 Test Review                                          Name: _______________________________
Atomic Evolution
1. Our knowledge of the atom has come a long way and continues to change as researchers develop better equipment to study atoms.
    Trace the evolution of Atomic Theory by summarizing each of the following scientist’s contributions to our understanding of the
    atom. When applicable, know a brief description of the experimentation that led to their discoveries. Democritus, JJ Thompson,
    Rutherford, Milikan, Dalton, and Bohr.
    a) Which scientist made this contribution?
       i. Discovered the electron using a cathode ray tube. _____________
      ii. Discovered the neutron _____________
     iii. Described the atom as a positively charged solid with electrons inside it like plums in a pudding______ _____
     iv. Found that the atom is mostly empty space with a small dense positively charged nucleus _____________
      v. Said everything is made of atoms which are indivisible, but could not prove his beliefs _____________
     vi. Measured the charge of an electron with his oil-drop experiment ______________________
    vii. Provided experimental evidence for the existence of atoms but was wrong about atoms being indivisible and that atoms of the
             same element are identical _____________
   viii. Found that electrons occupy almost all the volume of the atom _______________________
     ix. Said atoms combine in small whole number ratios _____________
    b) Who performed the Gold Foil Experiment?
    c) What was determined by the Gold Foil Experiment?
    d) Who is Democritus?
    e) Match the following scientists with their contributions to the atomic theory:
       i. Rutherford                 1. first to have ideas published about atom
      ii. Dalton                     2. said that electrons travel in fixed paths around the nucleus
     iii. Bohr                       3. Devised the Plum Pudding model
     iv. Thompson                    4. discovered that the atom is mostly empty space with a dense nucleus in the center
      v. Millikan          5. discovered the charge on the electron
    f) What is the Plum Pudding Model?
2. The Modern Quantum-Mechanical Model has replaced the “planetary Model” proposed by Bohr. Briefly explain the main
    components of the Quantum Model.
    a) Who are Planck, Schrodinger, and de Broglie? What are their contributions to the modern atomic theory (electrons)?
3. Complete the following table regarding the three main sub-atomic particles:
           Property                         Proton                           Neutron                       Electron
Symbol                                                                          no
Location in the atom
Charge                                         +1
Relative Mass                                                                                               1/1840

4.    Complete the following table using your knowledge of isotopic notation:
             Isotope                    Name                  # Protons                 # Electrons           #Neutrons
                99   Es

                                                                   84                                             127

                                   Actinium – 232

5.    How many protons, neutrons, and electrons are in a neutral atom of Zn-65?

6.    How many protons, neutrons, and electrons are in       ?
7.    How does a Lewis Structure differ from a Bohr Model? Draw Lewis Structures for each of the following elements, and then
      determine what ion the atom is most likely to form.
      (a) Sr      (b) Al             (c) S             (d) I       (e) Mn

8.    Write Noble Gas e- configurations for the following elements. When finished, circle the valence e-.
      (a) V       (b) Sb             (c) Cl            (d) Bi          (e) U
9.    What is an energy level?
10.   What does 5p2 tell us?
11.   What are the shapes of the s sublevel and the p sublevel?
12.   What is an atomic emission spectrum?
Chemistry Q3 Test Review                                         Name: _______________________________
                     (a) Who do elements differ?
13.    Element Z has 3 isotopes: 25.20% has a mass of 252.9 amu; 47.30% has a mass of 259.6 amu; 27.50% has a mass of 261.2 amu.
      What is the average atomic mass of this element?
14.   How many protons and electrons are in an atom of gallium with a mass number of 70?
15.   How many protons and electrons are in a neutral atom of S-32?
16.   What sub-atomic particle gives an element its identity?
17.   Define atomic number.
18.   Define atomic mass number.
19.   If the wavelength of a radio wave is 2.78 x 103 m, what is its frequency?
20.   Calculate the wavelength of a band of light with a frequency of 3.12 x 10 -7s-1
21.   How many valence electrons are in Rb? S? Cl?

Nuclear Chemistry
22. Write the balanced nuclear equation for the decay of Thorium-232 by alpha decay.
23. Write the balanced nuclear equation for the decay of potassium-39 by beta decay.
24. What effect does a gamma emission have on the mass and charge of a particle undergoing radioactive decay?
25. Define the Law of Conservation of Mass. How does this law apply to nuclear reactions?
26. What are the three types of radiation?
        a) What are their charges?
        b) Symbols?
27. Uranium-238 undergoes beta emission. Write the equation including the product.
28.   Complete the equation:
29.   How much of a 24 grams sample of uranium – 238 would remain after 21 minutes if the half life is 7 minutes?
30.   What is the difference between fusion and fission?
31.   Nuclear fission can undergo _________________ because one of the products is also a reactant.
32.   A target of bismuth-209 was bombarded with iron-58 for several days. One atom of meitnerium ( 266109Mt) was produced. How
      many neutrons were released in the process?
                    209       58      266         1
                        83Bi + 26Fe →    109Mt + ? 0n

33. After 42 days, 60.0 g of phosphorus-32 has decayed to 7.50 g. What is the half-life of phosphorus-32?
34. The radioisotope radon-222 has a half-life of 3.8 days. How much of a 78.3-g sample of radon-222 would be left after
    approximately 19.0 days?

Atomic Structure & Periodicity (con’t)
35. In which of the figures below was energy added to excite an electron? In which figure was energy released? How do you know?

                      Figure 1                                                        Figure 2

36. Give at least three properties of metals, non-metals, and metalloids. Then classify each of the following elements as a metal, non-
    metal, or metalloid. (a) Mg (b)Si (c) F (d) Th (e) Sb (f) Xe
37. Complete the blanks in the following sentences to make the statements TRUE:
        a. Atomic radius generally ___________ as you go across a period on the periodic table due to
             _________________________________. Atomic radius generally __________ as you go down a group due to
        b. Ionization energy generally ____________ as you go across a period on the periodic table due to
             ______________________________. Ionization energy generally ___________ as you go down a group due to
             _________________________. IIIA & VIA are exceptions to the trend.
        c. Electronegativity generally _____________ as you go across a period on the periodic table and ___________ as you go
             down a group. Fluorine is the ___________ electronegative element.
    g) Circle the bigger one:          a. Ca or Ca 2+         b. I or I-
    h) Circle the one with higher ionization energy        a. K or As      b. O or S

To top