True/False

1. Protons in the nucleus and electrons can attract to each other, which is the cause of the decrease in atomic size from left to right on the same row of the periodic table.
2. The atomic number of element is defined as the number of electrons of the element.
3. One atomic mass unit (amu) is 1/12 of the atomic weight of a carbon-12 atom, thus is a very small value in terms of the mass unit g.
4. The light from the sun contains all colors, thus this light energy is not quantized.
5. Electrons can be filled into orbitals in any order as long as you start from the smallest principle energy level to the largest in order.
6. The neutrons in the nucleus have no charge, which makes the nucleus of atoms neutral in charge.
7. Pauli exclusion principle states that an orbital can always be occupied with 2 electrons.
8. When you work on electron configuration, you just need to know the number of electron.  You don not need to know which atom you are dealing with.
9. The electron configuration 1s² 2s¹ means that there are one of s² and two of s¹ orbitals.
10. The maximum of 37 electrons can be filled in 5f sublevels (orbitals).
11. The color of light emitted by a hot substance is characteristic of the element in the substance, such as in the case of fireworks.
12. In his periodic table, Mendeleev arranged the elements in ascending order of atomic number.
13. The outermost sublevels, such as s, p, and d orbitals, are always partially filled, unless it is an inert gas.
14. The energy of all the sublevels in the principal energy level 3 is always lower than the energy of the sublevels in the principal energy level 4.
15. The elements can be roughly grouped in 4 blocks, s, p, d, and f blocks.
16. Ionization energy is the energy required to remove an electron from an atom in the state the atom is, such as Fe and Cu in the solid state, thus is very convenient to use to determine whether or not the atom is stable in that state.
17. If sufficient energy is provided, more than one electron can be removed from any atom.
18. The first ionization energy of Na is lower than that of Mg. However, the second ionization energy of Na is much higher than that of Mg.
19. Different elements can have the same electron configuration.
20. The electrons in noble gases cannot be removed at all.

1)    What is the maximum number of electrons that can be filled into the second principal energy level of an atom?
          (1) 4  (2) 6  (3) 8  (4) 10  (5) 18

2)     What is the maximum number of electrons that can be filled into the third principal energy level of an atom?
          (1) 4  (2) 6  (3) 8  (4) 10  (5) 18

3)    The maximum number of electrons and number of orbitals, respectively, in the 4d energy sublevel are
         (1) 6 and 3.  (2) 10 and 5.  (3) 2 and 1.  (4) 4 and 2. (5) 18 and 9.

4)    Isotopes of an element
        (1) contain the same number of neutrons.
        (2) have different nuclear charges.
        (3) must have the same atomic number.
        (4) must have the same mass.

5)    The number 60 in cobalt-60 represents
         (1) the atomic number.
         (2) the mass number.
         (3) the number of the protons.
         (4) the sum of the protons and electrons.
         (5) the number of the neutrons.

6)    The first ionization energy of sodium is 118.5 kcal/mol.  The second ionization energy compared with the first ionization energy is most probably
         (1) about the same. (2) about double. (3) much lower. (4) much higher.

7)    An orbital is best described as
          (1) an electron's path.  (2) a probability region of finding electrons  (3) an energy level.  (4) an energy sublevel.

8)    The nucleus of an atom is
          (1) positively charged and has a high density.
          (2) positively charged and has a low density.
          (3) negatively charged and has a high density.
          (4) negatively charged and has a low density.

9)    We would expect the electron configuration of oxygen to show ______ (how many?) unpaired electrons in its p orbitals according to the Hund's rule.
          (1) zero (2) one  (3) two  (4) three

10)    Which one has the electron configuration 1s² 2s² 2p⁶?
          (1) Na⁺ (2) Mg²⁺ (3) Ne  (4) F^–  (5) All of them!
        What is the number of electrons for each of the above atom/ion?

11)    Which element has the smallest first ionization energy?
          (1) P (2) Si  (3) Al  (4) Mg  (5) Na

12)    Which element has the lowest third ionization energy?
          (1) P (2) Si  (3) Al  (4) Mg  (5) Na

13)    Which element has the largest atomic radius?
          (1) F (2) Cl  (3) Br  (4) I   (5) At

For more "Which element" questions, please refer to the book!

14)    When Mg reacts with oxygen gas, you expect the formation of
          (1) MgO  (2) MgO₂ (3) Mg₂O (4) Mg₂O₃

15)    A metal that is an ingredient of the alloy used as implant material:
          (1) Ag (2) Cu  (3) Au  (4) Ti  (5) Hg

16)    The element in hemoglobin that is responsible of oxygen binding is
          (1) Fe (2) Cu  (3) Ni  (4) Zn  (5) Co

For more "what metal is in what protein/enzyme" questions, please refer to the lecture notes.

17)    We would expect the electron configuration of nitrogen to show ______ (how many?) unpaired electrons in its p orbitals according to the Hund's rule.
               (1) zero  (2) one   (3) two   (4) three  (5) four

18)    Which one has the electron configuration 1s2 2s2 2p6?
             (1) Na+  (2) Mg2+  (3) Ne   (4) F–    (5) All of them!

19)    Which element has the lowest third ionization energy?
             (1) P   (2) Si    (3) Al    (4) Mg   (5) Na

20)    A metal that is an ingredient of the alloy used as implant material:
             (1) Ag   (2) Cu   (3) Au   (4) Ti    (5) Hg

21)    Which element has the smallest second ionization energy? (How about the first and third IE?)
             (1) P   (2) Si    (3) Al    (4) Mg   (5) Na

Fill in the Blanks/questions and answers 

Write the symbol of the atom which has the electron configuration shown below.

 (a) 1s² 2s² 2p⁶ 3s¹  

 (b) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵ 

 (c) [Ar] 4s² 3d10 4p³  

 (d) [Xe] 6s¹  

The element ___ is widely used in the manufacture of electronic chips.  (P. 99)

The element ___ can be found in DNA, bones, and teeth.  The element itself is very sensitive to oxygen.  (P. 99)

The element ___ is toxic when it is taken into the body at certain level, but is an essential trace element for our health which can lower the risk of heart attack. (P. 101)

The metal ___ is found in vitamin B₁₂.  (P. 103)

The synthesis of ammonia (NH3) shown here is a very difficult process because of the inertness of N2.
           N₂ + 3H₂ <===> 2NH₃ + heat
However, it is one of the most important products in the chemical industry, where ammonia is formed at ______________ and ____________. (Discussed in the class.

Balance the following equation (3 points):

  C₃H₈  +  (A) O₂  ------->  (B) H₂O  +  (C) CO₂

     A = ____; B = ____; and C = ____

Write the electron configuration of the followings:
(Count the number of electrons for each atom or ion!)
 (a) Na
 (b) Na⁺
 (c) O^2–
 (d) Fe²⁺