KEY
Unit 2: Nature and Structure of Matter
Test Review
1. Define the following terms:
a. Chemical property – describe the ability of a substance to undergo a change that
transforms it into a new substance (how a substance reacts to something)
b. Physical property – property that can be measured or detected without changing the
composition of an object (appearance, odor, color, texture, density, melting point)
c. Intensive property – property of matter that is independent of quantity (it doesn’t
matter how much of something you have, only what the identity of the substance is)
d. Extensive property – property of matter that is quantity dependent (changes based on
how much of the substance you have)
2. Identify the described properties as Physical (P) or Chemical (C) and Intensive (I) or extensive
(E).
a. odorless P, I
e. soft, silver-white P, I
b. mass of 5.00 grams P, E
f. reacts violently with water C, I
c. tarnishes rapidly in air C, I
g. reacts with acid C, I
d. boiling point of 883 C P, I
3. Identify the major contribution of each of the following to current atomic theory (be sure to
include any model that they proposed and the experiment that they did):
a. Dalton – developed the basis for the modern atomic theory
i. All matter is composed of tiny particles called atoms. TRUE
ii. Atoms of an element are identical in size, mass and other properties. FALSE
(isotopes)
iii. Atoms cannot be created, destroyed or subdivided. FALSE (subatomic
particles)
iv. Atoms of different elements can combine in simple whole number ratios to
form compounds. TRUE
v. In chemical reactions, atoms are combined, separated or rearranged. TRUE
b. Rutherford - Gold foil experiment- expected all of the radiation to pass through and
was very surprised when some of the particles were deflected - led to the discovery of
the NUCLEUS (centrally located positive charge) and the concept that the atom is
mostly empty space. Also discovered the proton and neutron.
c. Bohr - His atomic model (planetary model) had atoms built up of successive orbital
shells of electrons. Electrons move between shells based on specific amounts of energy
being lost or gained.
d. Electron Cloud Model- This model is based on quantum mechanics which states that
you cannot know the speed and location of a particle. So this model shows the most
probable location of the electrons.
4. Be sure that you know how to graph and how to find slope.
Density Graph
Mass (g)
1.67
1.71
1.71
0.91
0.68
Slope:
Mass (g)
Data:
Volume
(cm3)
1.6
1.79
1.7
0.95
0.635
The slope of this graph represents
the density (mass/volume).
Volume (cm3)
This substance could be:
a) Gasoline (.7 g/mL)
b) Water (1 g/mL)
c) Magnesium (1.7 g/cm3)
5. Complete the following chart:
Nuclear
Atomic
Isotope Name
Symbol
Number
Carbon-13
Nitrogen - 17
Boron - 11
Francium - 223
13
11
223
# of
Protons
# of
Neutrons
# of
Electrons
C
6
13
6
7
6
N
7
17
7
10
7
B
5
11
5
6
5
Fr
87
223
87
136
87
6
17
7
Mass
Number
5
87
6. An element consists of three naturally occurring isotopes with the following mass numbers:
24, 25 and 26. The relative abundances of these three isotopes are 78.70, 10.13 and 11.17
percent respectively. Calculate the average atomic mass and identify the element. Show
your work!
(24 x .7870) + (25 x .1013) + (26 x .1117) = 24.3247 amu – Magnesium
7. The modern periodic table is arranged according to increasing atomic number.
8. The atomic number is equal to the number of protons.
9. The mass number is equal to the protons + neutrons.
10. Electrons in the outermost energy level are known as valence electrons and are available to
be lost, gained or shared when molecules are formed.
11. Write the full and shorthand electron configurations for
a. Beryllium
i. 1s22s2
ii.
[He] 2s2
b. Germanium
i. 1s22s22p63s23p64s23d104p2
ii.
[Ar] 4s23d104p2
c.
i.
ii.
[Kr] 5s24d10
Cadmium
1s22s22p63s23p64s23d104p65s24d10
d. Plutonium
i. 1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p67s25f6
ii. [Rn] 7s25f6
12. Write the electron dot diagrams for the following
a. Sodium
b. Phosphorus
c. Krypton
d. Magnesium
13. Fill in the following electromagnetic spectrum:
nm
nm
14. Describe the relationship between the following variables:
a. Wavelength and Frequency
Inversely related
b. Frequency and Energy
Directly related
c. Speed of different types of electromagnetic radiation
Constant
15. Briefly describe what happens that allows you to see colors in the flame test lab.
Heat energy from the flame is added to the atom, causing the electron to jump up to its
excited state. As the electron falls back to its ground state, it releases a photon of a specific
energy. This energy relates to a frequency and wavelength, which identifies the type/color of
radiation.
16. What is the energy of a quantum of light with a frequency of 4.31 X 1014 1/s or Hz?
17. A certain violet light has a wavelength of 413 nm. What is the frequency of the light?
18. What is the energy of light with a wavelength of 662 nm?