Name:
Covalent Bonding
Year 11 Science
Ruawai College 2014
Hydrogen gas, H2, is made up of two atoms of hydrogen that share electrons to
gain a full shell each. This is called covalent bonding.
Oxygen gas, O2, is made up of two atoms of oxygen that share electrons to gain
a full shell each. This is called covalent bonding.
Key Questions:
1.
How many electrons does a hydrogen atom have in its outer shell?
2.
How many electrons does a hydrogen atom need to have a full outer
shell?
3.
How many hydrogen atoms are needed to form a molecule of hydrogen?
4.
What is the formula of a molecule of hydrogen?
5.
How many electrons does an oxygen atom have in its outer shell?
6.
How many electrons does an oxygen atom need to have a full outer
shell?
7.
How many oxygen atoms are needed to form a molecule of oxygen?
8.
What is the formula of a molecule of oxygen?
9.
What do you think the line between the two hydrogen atoms stand for?
10.
What do you think the lines between the two oxygen atoms stand for?
11. How many electrons are shared by each chlorine atom when a molecule
of chlorine is formed?
12.
What do you think the line between the two chlorine atoms stand for?
13. How many electrons are shared by each nitrogen atom when a molecule
of nitrogen is formed?
14.
What do you think the lines between the two nitrogen atoms stand for?
Exercises:
15. Using the model of fluorine atom below draw a diagram of a fluorine
molecule.
16.
What is the formula of a fluorine molecule?
Key Questions:
17.
How many electrons does a hydrogen atom have in its outer shell?
18.
How many electrons does an atom of oxygen have in its outer shell?
19.
What is the formula of water?
Exercise:
20.
Explain the equation:
2H + O  H2O
Key Questions:
21.
How many electrons does a carbon atom need to gain a full shell?
22.
How many electrons does an oxygen atom need to gain a full shell?
23.
What is the formula of carbon dioxide?
Exercises:
24.
Explain the model:
O=C=O
25.
Explain the equation:
C + 2O  CO2
26.
Complete the sentences with the wordlist below:
electrons
electrons
molecules
H2
electrons
two two stable
compounds
two electrons
a.
Atoms which have incomplete outer electrons shells are not __________
b.
Some atoms lose __________ and become positive ions.
c.
Some atoms gain ___________ and become negative ions.
d.
Positive ions and negative ions bond ionically to form ionic __________.
e.
Some atoms share _______________ and bond covalently.
f.
When atoms bond covalently they form ______________ .
g.
When two hydrogen atoms bond covalently they form a hydrogen
molecule with the formula of _____ .
h.
When two oxygen atoms bond covalently they share _____ electrons to
gain full shells.
i.
Nitrogen atoms share three _________ to form a triple bond when they
form a nitrogen molecule.
j.
A water molecule is made from one oxygen atom and ____ hydrogen
atoms bonded covalently.
k.
A molecule of carbon dioxide if formed from one carbon atom and
_____ oxygen atoms bonded covalently.
27.
The models below show 5 molecules and 5 nobel gases:
a.
List the molecules.
b.
List the nobel gases.
c.
What is the difference between the molecules and the nobel gases?
28.
Above is a molecule. Use the model to answer the questions below.
a.
What kind of bond is shown in the diagram?
b.
What type of atoms is bonded to the oxygen?
c.
How do you know?
d.
Are the atoms that are bonded to the oxygen the same?
e.
How do you know?
f.
What kind of molecule is shown in the diagram?
g.
What is the formula of the molecule shown in the diagram?
h.
Draw a better diagram of this molecule (one that shows how the
electrons are shared between the atoms).
Name:
Covalent Bonding
Year 11 Science
Ruawai College 2014
Hydrogen gas, H2, is made up of two atoms of hydrogen that share electrons to
gain a full shell each. This is called covalent bonding.
Oxygen gas, O2, is made up of two atoms of oxygen that share electrons to gain
a full shell each. This is called covalent bonding.
Key Questions:
1.
How many electrons does a hydrogen atom have in its outer shell? 1
2.
How many electrons does a hydrogen atom need to have a full outer
shell? 2
3.
2
How many hydrogen atoms are needed to form a molecule of hydrogen?
4.
What is the formula of a molecule of hydrogen? H2
5.
How many electrons does an oxygen atom have in its outer shell? 6
6.
How many electrons does an oxygen atom need to have a full outer
shell? 8
7.
How many oxygen atoms are needed to form a molecule of oxygen? 2
8.
What is the formula of a molecule of oxygen? O2
9.
What do you think the line between the two hydrogen atoms stand for?
single covalent bond
10. What do you think the lines between the two oxygen atoms stand for?
two covalent bonds
11. How many electrons are shared by each chlorine atom when a molecule
of chlorine is formed? 1
12.
What do you think the line between the two chlorine atoms stand for?
Single covalent bond
13. How many electrons are shared by each nitrogen atom when a molecule
of nitrogen is formed? 3
14. What do you think the lines between the two nitrogen atoms stand for?
triple covalent bond
Exercises:
15. Using the model of fluorine atom below draw a diagram of a fluorine
molecule.
16.
What is the formula of a fluorine molecule? F2
Key Questions:
17.
How many electrons does a hydrogen atom have in its outer shell? 1
18.
How many electrons does an atom of oxygen have in its outer shell? 6
19.
What is the formula of water? H2O
Exercise:
20.
Explain the equation:
2H + O  H2O
Two hydrogen atoms and one oxygen atom are needed to form a molecule of
water
Key Questions:
21.
How many electrons does a carbon atom need to gain a full shell? 4
22.
How many electrons does an oxygen atom need to gain a full shell? 2
23.
What is the formula of carbon dioxide? CO2
Exercises:
24.
Explain the model:
O=C=O
Each oxygen atom shares two electrons with a carbon to form carbon dioxide
25.
Explain the equation:
C + 2O  CO2
Two oxygen atoms and one carbon atom share electrons to from CO2
26.
Complete the sentences with the wordlist below:
electrons
electrons
molecules
H2
electrons
two two stable
compounds
two electrons
a.
Atoms which have incomplete outer electrons shells are not stable
b.
Some atoms lose electrons and become positive ions.
c.
Some atoms gain electrons and become negative ions.
d.
Positive ions and negative ions bond ionically to form ionic compounds.
e.
Some atoms share electrons and bond covalently.
f.
When atoms bond covalently they form molecules .
g.
When two hydrogen atoms bond covalently they form a hydrogen
molecule with the formula of H2 .
h.
When two oxygen atoms bond covalently they share two electrons to
gain full shells.
i.
Nitrogen atoms share three electrons to form a triple bond when they
form a nitrogen molecule.
j.
A water molecule is made from one oxygen atom and two hydrogen
atoms bonded covalently.
k.
A molecule of carbon dioxide if formed from one carbon atom and two
oxygen atoms bonded covalently.
27.
The models below show 5 molecules and 5 nobel gases:
a.
List the molecules. N2 O2 CO2 H2 CH4
b.
List the nobel gases. Ar Ne He Kr Xe
c.
What is the difference between the molecules and the nobel gases?
Molecules are formed by two or more atoms bonded covalently – sharing
electrons to become stable
Nobel gases are single atoms that are stable because they have full energy
levels
28.
Above is a molecule. Use the model to answer the questions below.
a.
What kind of bond is shown in the diagram? covalent
b.
What type of atoms is bonded to the oxygen? hydrogen
c.
How do you know? Has one proton in its nucleus
d.
Are the atoms that are bonded to the oxygen the same? yes
e.
How do you know? Both have one proton in the nucleus
f.
What kind of molecule is shown in the diagram? water
g.
What is the formula of the molecule shown in the diagram? H2P
h.
Draw a better diagram of this molecule (one that shows how the
electrons are shared between the atoms).