Download Chemistry Review- Answer all questions on loose

Chemistry Review- Answer all questions on loose-leaf!!!!
1. Know the “KEY TERMS” from the vocabulary list given at the beginning of the unit. (41 key
terms)
2. Compare physical properties and chemical properties. (Similarities and differences)
Both properties describe a substance’s characteristics. All matter has both chemical and
physical properties. If a chemical change occurs, the new substance will have new chemical
and physical properties.
A physical property is a property that can be measured or describes a physical state. They
include color, mass, state, ability to conduct electricity, density, malleability, magnetism, etc.
A chemical property describes the changes made to the chemical makeup of a substance.
Properties include combustion, toxicity, flammability, etc.
3. Some of the physical properties of pure water are listed below. Which properties are
qualitative and which are quantitative?
a) Pure water is a very poor conductor of electricity. Qualitative
b) The volume of a sample of water is 26.8 mL. Quantitative
c) The normal boiling point of water is 100oC. Quantitative
d) Small depths of water are transparent to light. Qualitative
4. a) What properties indicate a physical change has occurred?
Change in physical state, size, shape, temperature, texture, etc.
b) What properties indicate a chemical change has occurred?
There has been a change to the chemical makeup of the original substance. A precipitate
may be formed, color change, heat is absorbed or given off, bubbles, gas is produced, a
substance disappears, a new odor, etc.
5. Which of the following are physical properties and which are chemical properties?
a) Lead is a relatively soft metal. Physical property
b) Copper wires are good conductors of electricity. Physical property
c) An iron nail rusts. Chemical property
d) Tums neutralizes stomach acid (heartburn). Chemical property
6. Classify each of the following as a physical change or a chemical change.
a) Frying an egg. Chemical change
b) Percolating coffee. Physical change (dissolving)
c) Letting socks dry. Physical change (evaporation)
d) Toasting bread. Chemical change
e) Growing a plant. Chemical change
f) Silver cutlery tarnishing over time. Chemical change
7. What were the major contributions of the following scientists to the study of chemistry:
a) Dalton (include Dalton’s atomic theory)
Main points are:
-
Elements are made of small particles called atoms.
Atoms of a given element are identical in size, mass, and other properties;
atoms of different elements differ in size, mass and other properties.
Atoms cannot be subdivided, created or destroyed.
Atoms of different elements combine in simple-whole-number ratios to form
chemical compounds.
In chemical reactions, atoms are combine, separated, or rearranged
b) Thomson
He discovered the electron and isotopes. He demonstrated that the atom consisted of
subatomic particles though his experiments with cathode rays. He proposed the Plum
Pudding Model where the atom is composed of electrons surrounded by a soup of
positive charge to balance the electrons negative charge.
c) Rutherford
He developed the Rutherford model as a model for the structure of the atom. He created
it in response to the plum pudding model made by Thomson, which he believed to be
incorrect. His model contained a nucleus, which contained a high concentration of
subatomic particles in a small area and made up the bulk of the atoms mass. The
electrons then surrounded the nucleus in a cloud.
d) Bohr
He took Rutherford’s model and further adapted it to create the Bohr-Rutherford Model.
The atom still has a small, positively charged nucleus made of protons and neutrons
surrounded by electrons that travel in circular orbits around the nucleus. Most of the
mass of the atom is found in the nucleus.
8. Compare and contrast the subatomic particles. (Size, location, charge, mass, atomic number,
atomic mass)
Electrons
 Located in shells
 -1 charge
 Smallest subatomic
particle
 No mass
 +1 charge
Protons
 Equal to
the atomic
number
 Located in the
nucleus
 Same relative
size
 Add to make up
the atomic mass
 Mass 1amu
 Located in
the atom.
 No charge
Neutrons
9. Write the chemical symbol of the following elements.
a) Potassium K b) Calcium Ca
f) Zinc
Zn g) Tin
Sn
c) Uranium
h) Silicon
U d) Lead
Pb e) Copper
Si i) Magnesium Mg j) Argon
Cu
Ar
10. Write the name of the element for the following chemical symbols.
a) P Phosphorus b) Ar Argon
f) W Tungsten
g) Ni Nickel
c) Fe Iron
h) I Iodine
d) Hg Mercury
i) B Boron
e) Au Gold
j) Ag Silver
11. Determine the number of protons, electrons and neutrons from the following information:
a) Atomic Number of 78, Atomic Mass of 195. P = 78
b) Atomic Number of 60, Atomic Mass of 144 P = 60
c) Atomic Number of 114, Atomic Mass of 289 P = 114
E = 78 N = 117
E = 60 N = 84
E = 114 N = 175
12. Determine the atomic number and atomic mass from the following information.
a) Protons = 32
b) Protons = 40
c) Protons = 101
Electrons = 32
Electrons = 40
Electrons = 101
Neutrons = 41
Neutrons = 51
Neutrons = 157
#32 73 amu
#40 91 amu
#101 258 amu
13. Draw Bohr diagrams for the following elements and properly label them with their element
symbol, valence, period and family.
a) Lithium
P=3
N=4
Li
Valence: 1
Period: 2
Family: 1
b) Oxygen
P=8
N=8
O
Valence: 6
Period: 2
Family: 6
c) Magnesium
P = 12
N = 12
Mg
Valence: 2
Period: 3
Family: 2
14. How does electron structure of the noble gases help to explain their chemical properties?
Noble gases are stable, generally non-reactive elements. Their structure explains this
characteristic seen in the family. Their valence shells are always full, leaving the atom no
desire to gain or lose electrons by reacting with other atoms.
15. List 3 properties of each chemical family. Organize the information into a chart like the
one shown below.
Alkali Metals
 Li, Na, K,
Rb, Cs, Fr
 Highly
reactive,
unstable
 Shiny,
silvery
 React with
water to
produce
alkaline
solutions
 1 valence
electron
 Softer than
other
metals
Alkaline
Earth Metals
 Be, Mg, Ca,
Sr, Ba, Ra
 Very
reactive
 Occur
naturally
 Silvery, soft
metals
 2 valence
electrons
Transition
Metals
 Ag, Au, Co,
Cu, etc
 38
elements
in the
group
 Metals
 Ductile
 Malleable
 Conduct
electricity
and heat
 Valence
electrons
are
special!
 Strong
 Shiny
Chalcogens
Halogens
Noble Gases
 O, S, Se,
Te, Po
 A.K.A. the
oxygen
family.
 Tend to
form
copper-ore
or other
ores.
 6 valence
electrons
 Nonmetals
 Se, Te, Po
are
metalloid
semiconductors
 F, Cl, Br, I,
At
 7 valence
electrons
 Very
unstable
and
reactive
 Do not
conduct
electricity
 Bind with
alkali
metals or
themselves
!
 He, Ne, Ar,
Kr, Xe, Rn
 Very, very
low
reactivity
 stable
 Full
valence
shell
 Colorless
and
odorless
 Can be
excited by
electricity
to create
interesting
colors.
16. a) Who created the first version of the periodic table? Dmitri Mendeleev
b) What was this organization of this table based on? The organization of that table was
based on the atomic mass and properties of the elements.
c) The modern periodic table is organized into rows and columns. What are the rows and
columns called on the modern periodic table? Rows are called periods and the columns
are called groups.
d) What information do the periods give you about the structure of all of the atoms in that
period? The period numbers indicate the number of electron shells in the atom.
e) What information do the groups give you about the structure of all of the atoms in that
group? The group numbers indicate the number of outer-shell electrons (valence
electrons) of all the atoms in the group.
17. a) Compare the properties of metals and nonmetals. (Similarities and differences)
Similarities: color varies, many elements are not magnetic, metalloids include elements
with properties of metals and nonmetals.
Metals: shiny, malleable, conductors
Nonmetals: dull, brittle, do not conduct electricity.
b) List all the metalloids on the periodic table and state 2 characteristics of metalloids.
Each of these elements are metalloids: Boron (B), Silicon (Si), Germanium (Ge), Arsenic
(As), Antimony (Sb), Tellurium (Te), Polonium (Po), Astatine (At).
Some characteristics of metalloids are:





Can be shiny or dull
May conduct electricity
Poor conductors of heat
They are brittle (easily breakable)
Not ductile (cannot be drawn into a long thin wire)
18. a) Which families are the most reactive on the periodic table? Why?
The alkali metals (group 1) and the halogens (group 17) are the most reactive because the
alkali metals have one electron in their outer shell that they desperately want to get rid
of. The halogens have 7 outer shell electrons and they need only one extra electron to
complete its outer shell.
b) Which families are the least reactive? Why?
The noble gases (group 18) are the least reactive family because they have a full outer
shell.
19. What is the difference between elements and compounds?
Elements are a type of pure substance that cannot be broken down into simpler parts by
ordinary chemical needs. (Ex. Oxygen, gold)
Compounds are pure substances made up of two or more elements that are chemically
combined. (Ex. CO2 consists of 2 elements, carbon and oxygen)
20. What information is given in a chemical formula?
The information given in a chemical formula is the name of each element in the compound
and the number of atoms of each element in the compound.
21. State the name and number of each element in the following compounds:
a) AlN
Aluminum 1
Nitrogen 1
b) SbH3
Antimony 1
Hydrogen 3
e)(UO2)2(OH)4
Uranium 2
Oxygen 8
Hydrogen 4
f) Zn(CN)2
Zinc 1
Carbon 2
Nitrogen 2
c) Ca(NO3)2
Calcium 1
Nitrogen 2
Oxygen 6
g) SO2Cl2
Sulfur 1
Oxygen 2
Chlorine 2
d)(C2H5)2
Carbon 4
Hydrogen 10
h) KTiOPO4
Potassium 1
Titanium 1
Oxygen 5
Phosphorus 1
22. In each pair of elements, which is the more reactive element? Explain your choice based on
the properties of the periodic table.
a) Barium or Calcium - Both Ba and Ca are part of group 2, the alkaline earth metals. The
reactivity increases as you move down the group. Calcium is less reactive as it is in
period 4 and Barium is in period 6.
b) Boron or Argon - Boron is more reactive than argon since argon is a noble gas. Noble
gases are the least reactive elements since they have complete outer shells. Boron is also
more reactive because it only has 3 outer shell electrons and must react with something
to end up with a full shell.
c) Sodium or Magnesium - Both Na and Mg are in the same period on the periodic table, but
Na has only one valence electron (group 1-Alkali metals) making it violently reactive. Na is
very close to a full electron shell, it only has to lose one electron and that will happen
more readily than Mg losing two (group 2 –Alkaline earth metals). It is harder for Mg to
lose two electrons so the reaction isn’t quite so volatile.
23. a) What are isotopes?
Isotopes are any of two or more forms of an element that have the same number of
protons but a different number of neutrons.
b) Explain how the existence of different isotopes of an element would affect the element’s
relative mass in the periodic table?
An element’s relative mass in the periodic table is an average of the masses of the
isotopes of that element. The proportion of each isotope is factored into the element’s
atomic mass.
c) There are 10 isotopes of tin. State at least two ways in which atoms of these isotopes
would be alike?
All of the isotopes of tin would have the same atomic number, the same number of
protons and the same number of electrons (if the atom is neutral)
d) Naturally occurring isotopes of both rubidium (Rb) and strontium (Sr) are found with the
same mass number, 87. Explain how this is possible.
Rb and Sr could have the same atomic mass because of the different number of neutrons
in each atom. Rb has an atomic number of 37, 37 protons and 50 neutrons (if the atomic
mass is 87 amu). Sr has an atomic number of 38, 38 protons and 49 neutrons (if the
atomic mass is 87 amu).
24. a) Which element was likely discovered first, Neon, Nickel or Nitrogen? Explain.
Nitrogen was likely discovered first because its chemical symbol is a single letter, where
as both Neon and Nickel have two letters for their symbols. Both nickel and neon would
only have N if either was discovered prior to nitrogen.
b) Which element was likely discovered first, Nobelium or Niobium? Explain.
Based on naming rules Nobelium was likely discovered before Niobium. N was taken for
nitrogen, so Nobelium’s symbol is No. Niobium could not be given N due to nitrogen, or
Ni due to nickel, so the first possibility would have been No, but No must have been
taken by Nobelium so Niobium’s symbol is Nb.
c) If a new element “Brainium” were discovered, what might the element symbol be?
Explain your choice.
“Brainium” would need have Bn as its chemical symbol. B is taken by Boron, Br is taken
by Bromine, Ba is taken by Barium and Bi is taken by Bismuth. The symbol must be 2
letters, so Bn would be the next available set of letters for Brainium.
25. Complete the table.
Element
Name
Element
Symbol
Atomic
Number
Atomic
Mass
Number
of
Protons
Number
of
Electrons
Number
of
Neutrons
Magnesium
Mg
12
24
12
12
12
Lithium
Iodine
Oxygen
Sodium
Li
I
O
Na
3
53
8
11
7
127
16
23
3
53
8
11
3
53
8
11
4
74
8
12
Group
Period
2
3
1
17
16
1
2
5
2
3
Family Name
Alkaline Earth
Metals
Alkali Metals
Halogen
Chalcogen
Alkali Metal