4.Which scientist described the electrons as traveling in certain orbits or energy levels? a. Dalton
b. Rutherford
c. Thomson
d. Bohr

5.In a famous experiment, scientists bombarded a very thin gold (Au) foil with positively charged alpha particles. They found that most of the alpha particles passed right through the Au foil. However, a few of the alpha particles were deflected or bounced back toward the source. How did these scientists explain their results?

a. Negative charges are spread throughout the atom.
b. Negative charges are located in the tiny nucleus of the atom.
c. Positive charges are located in the tiny nucleus of the atom.
d. Positive charges are spread throughout the atom.

6.The atomic mass represents the weighted average of an element’s

a. Ions
b. mass numbers
c. atomic numbers
d. isotopes

7.The number of protons is represented by the element’s

a. atomic number
b. mass number
c. atomic mass
d. isotope

8.The number of protons plus neutrons is represented by the

a. atomic number
b. mass number
c. atomic mass
d. isotope

9.How many valence electrons would an atom of Chlorine have?

a.2
b.3
c.7
d.8

10.An element is found to have 2 electrons in the 3rd energy level. What is this element?

a. Boron
b. Magnesium
c. Fluorine
d. Argon

11.Which shows the order of decreasing atomic size?

a. Si, Al, Mg, Na
b. I, Br, Cl, F
c. Be, Mg, Ca, Sr
d. C, P, Se, I

12.Which of the following elements has the highest ionization energy and why?

a. Argon because it has more protons in the nucleus.
b. Argon because it has a full valence shell.
c. Chlorine because it only needs one valence electron to fill its valence shell.
d. Chlorine because it attracts electrons better.

13.Which shows the order of increasing ionization energy?

a. Si, Al, Mg, Na
b. Ga, Ge, As, Se
c. Be, Mg, Ca, Sr
d. F, Cl, Br, I

14.Identify the reason why atoms decrease in size(atomic radius)across a period on the Periodic Table.

a. Gravity pulls the electrons in towards the nucleus.
b. Increase in energy levels increases the attraction and thus pulls electron cloud in.
c. Increasing strong positive nuclear charge from the nucleus pulls in the negative electron clouds and increases with the increase in protons and electrons.
d. Electrons lose energy and collapse with an increasing number of electrons and protons.

15.What is the shielding effect?

a. The neutrons shield protons from the attraction of the electrons from the first energy level.
b. Valence electrons are shared equally between atoms.
c. The repulsion of electrons in the same energy level.
d. The inner-core electrons shield outer-core electrons from the attraction to the atom’s nucleus.

16.Which statement is an accurate description of elements from Period 3 on the periodic table?

a. It contains elements with the same number of 3 protons.
b. It contains elements with the same number of3valence electrons.
c. It contains elements with the outermost protons in the same 3rd energy level.
d. It contains elements with the outermost electrons in the same 3rd energy level.

17.The column that an element is located in tells us

a. the total number of valence electrons an atom has.
b. the total number of energy levels an atom of that element has.
c. the highest energy level an atom of that element has.
d. both b & c.

18.The Halogen family of elements all have 7 valence electrons. Which column would they be in?

a.01 (IA)
b.02 (IIA)
c.4 (IVA) or 14
d.7 (VIIA) or 17

19.The Alkali and Alkaline Earth metals belong to which columns, respectively?

a. Column IA & IIA
b. Column VIIA & Column VIIIA
c. Column IIIA & IVA

20.What do carbon and silicon have in common?

a. They belong to the same column (family), therefore they have the same number of valence electrons.
b. They belong to the same column (family), therefore they have the same number of total electrons.
c. They belong to the same column (family), therefore they have the same number of energy levels.
d. They belong to the same column (family), therefore they have the same number of protons.

21.Electromagnetic radiation can take the form of which of the following types of waves

a. Heat
b. Light
c. Ultraviolet
d. All of the above

24.In order to go to a lower energy orbit, an electron

a. Must disappear
b. Must combine with other electrons
c. Lose energy of a specific amount
d. Must be transferred to another atom

25.Please choose the correct sequence that describes the excitement of an atom.
1. Such an electron transition raises the atom from the ground state to the excited state.
2. When energy is added to an atom from an outside source, its electrons move to a higher energy level (orbit)
3. As a result, the atom emits a photon.
4. When the atom is in an excited state, the electron can drop from the higher energy level to a lower energy level.

a.1, 2, 3, 4
b.4, 3, 2, 1
c.2, 1, 4, 3
d.3, 4, 1, 2