Ch. 4 - Chemistry Review
Part I. Complete the following chart based on the periodic table and your knowledge of atomic structure
Element
Hydrogen
Helium
Lithium
Beryllium
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
Sodium
Magnesium
Aluminum
Silicon
Phosphorus
Sulfur
Chlorine
Argon
Potassium
Calcium
Carbon-14
Sodium-23
Element
Symbol
Atomic
Number
Atomic
Weight
# of
# of
protons neutrons
(p)
(n)
# of
electrons
(e-)
# of electrons
in outer most
layer (shell)
Part II. For each of the following elements / isotopes use the information from the previous chart and
periodic table to
1) Draw the nucleus and put the correct number of protons & neutrons in the nucleus
2) Draw the electron shells of each atom and place the correct number of electrons in each level
1. Hydrogen
2. Helium
3. Beryllium
4. Carbon
5. Oxygen
6. Carbon-14
7. Sodium
8. Sulfur
9. Chlorine
10. Boron-11
Part III. Based on the given molecule – identify if the bond between the elements is either covalent or
ionic and explain using an atomic diagram.
1. Cl2
2. KCl
3. NaF
4. CO2
Part IV. Balance the following chemical equations, so that the same number of elements on the
reactant side is equal to the elements on the product side.
1. ___ H2 + ___O2  ____ H2O
6. ___ Al + ___ HCl  ___ H2 + ___ AlCl3
2. ____ K + _____Cl2  ______ KCl
7. ___Ca(OH)2 + ___ HF  ___ H2O + ___CaF2
3. ____ H2 + ____ NO  ___ H2O + ___N2
8. ___ Zn + ___ H2CO3  ___ZnCO3 + ___H2
4. ___AlBr3 + ___ Cl2 ___ AlCl3 + ___ Br2
5. ___Cu + ___H2SO4 __ CuSO4 + ___ H2O + ___SO2
Part V. Answer the following questions about water
1. Why is water such an important molecule to living things?
2. Describe the chemical make up and type of bonding found in water molecules.
3. Explain why the hydrogen and oxygen atoms don't share electrons equally in a water molecule.
4. Sketch a molecule of water showing the charges on the molecule.
5. Name 2 types of compounds that dissolve well in water.
6. What happens when an ionic compound such as sodium chloride (table salt) dissolves in water?
7. Water molecules are ___________ to other water molecules.
8. Water molecules attracting other water molecules is called _________________.
9. Cohesion of water molecules produces ________________ tension making water seem like it has a
"skin" on it. Surface tension enables some _____________ to walk across the surface of the water.
10. Water molecules attracting other types of molecules is called _________________.
11. Adhesion and cohesion together enable water molecules to move ____________ through narrow
tubes against the force of gravity.
12. The above property of water is called _________________.
13. Give an example of an organism using capillarity.
14. What must be true for water to change temperature? To change state?
ANSWERS
Part I
Element
Element Atomic
Symbol Number
Atomic
Weight
Hydrogen
Helium
Lithium
Beryllium
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
Sodium
Magnesium
Aluminum
Silicon
Phosphorus
Sulfur
Chlorine
Argon
Potassium
Calcium
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
1
4
7
9
11
12
14
16
19
20
23
24
27
28
31
32
35
40
39
40
Element
Hydrogen
Helium
Lithium
Beryllium
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
Sodium
Magnesium
Aluminum
Silicon
Phosphorus
Sulfur
Chlorine
Argon
Potassium
Calcium
Orbitals
1s1
1s2
1s2 2s1
1s2 2s2
1s2 2s22p1
1s2 2s22p2
1s2 2s22p3
1s2 2s22p4
1s2 2s22p5
1s2 2s22p6
1s2 2s22p63s1
1s2 2s22p63s2
1s2 2s22p63s23p1
1s2 2s22p63s23p2
1s2 2s22p63s23p3
1s2 2s22p63s23p4
1s2 2s22p63s23p5
1s2 2s22p63s23p6
1s2 2s22p63s23p64s1
1s2 2s22p63s23p64s2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
# of
# of
protons (p) neutrons
(n)
1
0
2
2
3
4
4
5
5
6
6
6
7
7
8
8
9
10
10
10
11
12
12
12
13
14
14
14
15
16
16
16
17
18
18
22
19
20
20
20
# of
electrons
(e-)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
# of electrons
in outer most
layer (shell)
1
2
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
Part II. For each of the following elements / isotopes use the information from the previous chart and
periodic table to
1) Draw the nucleus and put the correct number of protons & neutrons in the nucleus
2) Draw the electron shells of each atom and place the correct number of electrons in each level
1. Hydrogen
2. Helium
3. Beryllium
4. Carbon
5. Oxygen
6. Carbon-14
7. Sodium
8. Sulfur
9. Chlorine
10. Boron-11
Part III. Based on the given molecule – identify if the bond between the elements is either covalent or
ionic and explain using an atomic diagram.
1. Cl2
2. KCl
3. NaF
4. CO2
Part IV. Balance the following chemical equations, so that the same number of elements on the
reactant side is equal to the elements on the product side.
1. 2 H2 + ___O2  2 H2O
6. 2 Al + 6 HCl  3 H2 + 2 AlCl3
2. 2 K + _____Cl2  2 KCl
7. ___ Ca(OH)2 + 2 HF  2 H2O + ___CaF2
3. 2 H2 + 2 NO  2 H2O + ___N2
8. ___ Zn + H2CO3  ___ZnCO3 + ___H2
4. 2 AlBr3 + 3 Cl2  2 AlCl3 + 3 Br2
5. ___Cu + 2 H2SO4 __ CuSO4 + 2 H2O + ___SO2
Part V. Answer the following questions about water
1. Why is water such an important molecule to living things?
All living things are made of water, water crucial for metabolism functions (energy)
2. Describe the chemical make up and type of bonding found in water molecules.
Polar covalent - outer two electrons of hydrogen are pulled toward oxygen
3. Explain why the hydrogen and oxygen atoms don't share electrons equally in a water molecule.
Oxygen has a greater electro-negativity and pulls the hydrogen atoms to itself - leaving the
hydrogen molecules as a positive end.
4. Sketch a molecule of water showing the charges on the molecule.
positive on the hydrogen sides and negative on the oxygen side
5. Name 2 types of compounds that dissolve well in water.
Sugar and salt
6. What happens when an ionic compound such as sodium chloride (table salt) dissolves in water?
The sodium ions are attracted to the oxygen side of the molecule and chlorides are attracted to the
hydrogen
7. Water molecules are attracted to other water molecules.
8. Water molecules attracting other water molecules is called cohesion.
9. Cohesion of water molecules produces Surface tension making water seem like it has a "skin" on it.
Surface tension enables some organisms to walk across the surface of the water.
10. Water molecules attracting other types of molecules is called adhesion.
11. Adhesion and cohesion together enable water molecules to move upward through narrow tubes
against the force of gravity.
12. The above property of water is called capillary action.
13. Give an example of an organism using capillarity. Water is moved up the roots and stems of a
plant.
14. What must be true for water to change temperature? To change state? Energy must be lost or
added
Zinc and lead (II) nitrate react to form zinc nitrate and lead.
Zn + Pb(NO3)2  Zn(NO3)2 + Pb
_______________________________________________________________
2)
Aluminum bromide and chlorine gas react to form aluminum chloride and bromine gas.
2 AlBr3 + 3 Cl2  2 AlCl3 + 3 Br2
_______________________________________________________________
3)
Sodium phosphate and calcium chloride react to form calcium phosphate and sodium
chloride.
2 Na3PO4 + 3 CaCl2  6 NaCl + Ca3(PO4)2
_______________________________________________________________
4)
Potassium metal and chlorine gas combine to form potassium chloride.
2 K + Cl2  2 KCl
_______________________________________________________________
5)
Aluminum and hydrochloric acid react to form aluminum chloride and hydrogen gas.
2 Al + 6 HCl  3 H2 + 2 AlCl3
_______________________________________________________________
6)
Calcium hydroxide and phosphoric acid react to form calcium phosphate and water.
3 Ca(OH)2 + 2 H3PO4  Ca3(PO4)2 + 6 H2O
_______________________________________________________________
7)
Copper and sulfuric acid react to form copper (II) sulfate and water and sulfur dioxide.
Cu + 2 H2SO4  CuSO4 + 2 H2O + SO2
_______________________________________________________________
8)
Hydrogen gas and nitrogen monoxide react to form water and nitrogen gas.
2 H2 + 2 NO  2 H2O + N2
1 Ca(OH)2 + 2 HF  2 H2O + CaF2 (CaF2 precipitates)
2)
1 Pb(NO3)2 + 1 K2CrO4  2 KNO3 + PbCrO4 (PbCrO4 precipitates)
3)
2 NaC2H3O2 + 1 H2SO4  Na2SO4 + 2 CH3COOH (no precipitate)
4)
3 Cu(OH)2 + 2 H3PO4  6 H2O + Cu3(PO4)2
copper (II) phosphate precipitates
5)
2 AgNO3 + 1 Na2CO3  Ag2CO3 + 2 NaNO3 (Ag2CO3 precipitate
6)
1 Zn + 2 H2CO3  ZnCO3 + H2 (ZnCO3 precipitates)
7)
Pb(OH)2 + Hg2S  no reaction; neither reagent is soluble in water
Part III. Based on the given molecule – draw the bond between the elements if it is either covalent or
ionic and explain any change in charges using an atomic diagram.
1. Cl2
2. KCl
3. NaF
4. CO2
Part IV. Write the Lewis dot structure for each of the following atoms
1.
5.
H
2.
9.
F
6.
He
3.
10.
N
7.
Li
4.
Na
11.
B
8.
Be
Mg
Ar
12.
C
K
Part IV. Write the Lewis dot structure for each of the following atoms
1.
5.
9.
2.
6.
10.
3.
7.
11.
4.
8.
12.