SCIENCE 9
Name: ____________________________________________
Teacher: __________________________________________
Grade and Section: _________________
Score: _______________
LEARNING ACTIVITY SHEET QUARTER 2, WEEK 4 & 5
CHEMICAL BOND & NAMING OF COMPOUNDS
Learning Competencies:
1. Recognize different types of compounds (ionic or covalent) based on their properties such as melting
point, hardness, polarity, and electrical and thermal conductivity.
2. Explain how ions are formed.
Background Information for Learners
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A chemical bond is a force of attraction that holds atoms together in a compound.
When atoms bond together, their valence electrons participate in the formation of chemical bonds.
Valence electrons are the outermost electrons of an atom.
Bonding lowers the potential energy between positively and negatively-charged particles.
Law of Conservation of Mass
 It states that mass can neither be created nor destroyed. When chemical reactions happen, the total mass
of the reactants should be equal to the total mass of the products.
Law of Definite Proportions
 It states that a substance, regardless of amount and origin, should have a fixed composition of its
constituent atoms.
Law of Multiple Proportions
 It states that when two elements combine with each other to form two or more compounds, the ratios of
the masses of one element that combines with the fixed mass of the other are simple whole number
ratios.
Lewis Electron-Dot Symbol
 It is a method to represent valence electrons of elements.
 It is composed of an element symbol and the dots around the element symbol.
 The element symbol represents the nucleus of the atom and the inner electrons that do not participate in
bonding.
 The number of dots around the chemical symbol represents the number of valence electrons.
Elements in the same group have the same number of valence electrons.
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SCIENCE 9
The noble
gases (Group
18
or
8A)
are
known
to
be
the
most
stable
atoms.
- They are chemically inert, or do not form chemical bonds with other atoms, except in some conditions.
- The noble gases all have an electron configuration of ns2np6 at their valence shells
Notice that at the valence shell of the noble gases, all of them have 8 electrons in their valence shell.
 The tendency of an element to gain, lose, or share electrons to attain 8 electrons on its valence shell
during chemical bonding is called the octet rule.
 An exception to the octet rule is hydrogen which follows the duet rule. It only needs two electrons on
its valence shell for bonding to occur.
 Elements such as boron and beryllium attain stability if they are less than an octet.
 There are also atoms which can have more than an octet. Examples are sulfur and phosphorus, and other
elements with periods at 3 and above.
FORMATION OF IONIC COMPOUNDS AND COVALENT MOLECULAR COMPOUNDS
Compounds are formed between the chemical combinations of two or more elements. To distinguish
between the types of compounds, one should first take note of the type of elements that are chemically combined.
Figure 2 shows the compounds formed based on the type of elements combined.
Figure 2: Compounds Formed Based on the Types of Elements Combined
To determine if an element is a metal, non-metal, or metalloid one should refer to their location in the
periodic table. Figure 3 shows the location of these three types of elements. The pink colors are the metals, the
blue ones are nonmetals and the green elements are the metalloids. As you can see, most elements are metals and
placed on the left side of the periodic table except for Hydrogen. On the right side are the nonmetals separated
by a stair-like barrier of elements which are the metalloids or semi-metals.
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SCIENCE 9
The Ionic Compounds
Based on Figure 2, Ionic compounds are formed between a metal and a nonmetal. The chemical
combination between the two types of elements results in the formation of ionic bonds between the atoms. Ionic
bonds are the electrostatic force of attraction that holds cations (positively charged atom) and anions (negatively
charged atoms) together.
Sodium Chloride (NaCl) or table salt is an example of an ionic compound. It is the combination of Sodium
(a metal) and Chlorine (a nonmetal). Sodium becomes a cation (Na+) as it loses an electron and transfers to the
chlorine atom. Chlorine gaining the electron becomes an anion (Cl-) and eventually, an ionic bond is formed
holding these ions together.
https://commons.wikimedia.org/wiki/File:207_Ionic_Bonding-01.jpg
Figure 3: Ionic Bonding between Sodium and Chlorine
The table below show examples of ionic compounds and their uses.
Table 1: Common Ionic Compounds and their Uses
Ionic Compound
Chemical
Importance and Uses
Formula
Potassium iodide
KI
Iodized salt used for thyroid health
Sodium fluoride
NaF
An ingredient in toothpaste that helps prevent cavities and tooth
decay.
Sodium bicarbonate
NaHCO3
Baking soda; used in baking and as an antacid to reduce stomach
acid, treats indigestion and upset stomach.
Sodium hydroxide
NaOH
Used as a cleaning agent, it is the component of soap and detergents.
Barium Chloride
BaCl2
Used in making fireworks releasing the green-colored explosions
The Covalent Molecular Compounds
Covalent molecular compounds or simply covalent compounds are substances that are formed from
the chemical combination of two or more nonmetallic elements. Based on Figure 2, it could be between a nonmetal
and another nonmetal, or a metalloid and a nonmetal. Table sugar or sucrose (C12H22O11) is an example of a
covalent molecular compound. It is a combination of carbon, hydrogen, and oxygen atoms.
In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds.
Unlike ionic bonds, in which electrons completely transfer from one atom to another, covalent bonds share their
valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms
holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has
the properties of the compound.
Figure 4 shows the sharing of electrons between Hydrogen and Oxygen atoms to form the water (H 2O)
molecule. This sharing of electrons results in a covalent bond between atoms.
Figure 4: Covalent bonding between H and O to form water molecule
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SCIENCE 9
4
There are millions of covalent molecular compounds most are formed by carbon and found in living things.
The smallest, simplest covalent compounds have molecules with just two atoms referred to as binary molecular
compounds.
Here are some examples of Covalent Molecular Compounds and their uses
Table 2:Lists of Some Covalent Molecular Compounds and their Importance.
Covalent
Molecular
Compound
Chemical
Formula
Methane
CH4
Ammonia
NH3
Ozone
Carbon dioxide
Water
O3
CO2
H2O
Importance and Uses
An odorless, colorless gas used mainly as fuel to make heat and light.
Ammonia is used as a refrigerant gas, for purification of water supplies, and in the
manufacture of plastics, explosives, textiles, pesticides, dyes, and other chemicals.
Ozone is a gas that occurs naturally in trace amounts in the stratosphere. It protects
life on Earth from the harmful UV rays of the son. But this gas is toxic to living
organisms at ground level.
It is an essential gas for plant and animal processes – like photosynthesis and
respiration. But the excessive amount in the atmosphere is unsafe as it is a
greenhouse gas.
In the industry, carbon dioxide in liquid and solid form is used as a refrigerant, in
fire extinguishers.
One of the most important substances, perhaps in the universe. Water exists in three
states of matter and is essential to life processes, as our body needs water for all
cells, tissues, organs to help regulate body temperature and maintain bodily
functions.
It is also essential for daily and domestic use. Water also plays an important role in
the balance of the ecosystem.
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SCIENCE 9
Activity 1: Chemical Bonding
Ionic Bond
Polar Covalent Bond
Non-Polar Covalent Bond
Metallic Bond
between a Metal and Non-Metal
between a Non-Metal and Non-Metal
between a Non-Metal and Non-Metal
between a Metal and Metal
(M + NM)
(NM + NM)
(NM + NM)
(M+ M)
Determine if the elements in the following compounds are metals or non-metals. Describe the type of bonding
that occurs in the compound.
Compound
Name of the
Compound
NO2
Nitrogen dioxide
Element 1
Element 2
(metal or nonmetal?)
(metal or nonmetal?)
Bond Type
N = non-metal
O = non-metal
Polar covalent
NaCl
SO2
PO43-
MgBr2
CaO
H2O
K2O
Cu-Zn alloy
O2
CuCl2
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SCIENCE 9
Chemical nomenclature is the systematic way of naming compounds. The International Union of Pure and
Applied Chemistry or IUPAC is an international federation of chemists responsible for naming elements and
standardized measurements in chemistry.
How are ionic compounds and binary covalent compounds named from their chemical formulas?
Naming Binary Ionic Compounds
Binary ionic compounds are compounds that are composed of two ions: a cation and an anion. In naming these
compounds, the main rule is to name the cation first, followed by the anion.
When you look at the periodic table of elements, common cations are the elements in Group IA-IIIA. These
elements have definite charges. Others such as copper and manganese, have varying charges. Thus, in naming
cations with varying charges, you include the charge in a parenthesis.
Anions are evenly divided between the monatomic anions and polyatomic anions. Naming anions takes some
learning. If they are a monatomic anions, their parent atoms name will be changed to finish in “–ide”; such as
chloride, fluoride, and oxide.
Polyatomic anions, however, needs some familiarization. You can check the figure below for the list of
polyatomic ions and their names.
Examples:
Example 1: cation (+) and anion (-)
NaCl
ions formed: Na+ and Clname of compound: sodium chloride
Example 2: cation with varying charge and anion:
CuCl2
ions formed: Cu2+ and Clname of compound: copper (II) chloride
Example 3: cation and polyatomic anion
NaOH
ions formed: Na+ and OHname of compound: sodium hydroxide
A binary COVALENT compound has two parts: the names of the atoms in the molecule and the number of
atoms present. The chemical formula of the binary compound gives the symbols of each atom with a subscript
number indicating the number of atoms for each nonmetal.
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SCIENCE 9
In naming a binary molecular compound, follow the steps below.
Step 1: Identify the names of the atoms present.
Step 2: The name of the second element in the formula ends in “-ide." For example, if chlorine is the second
element, then it is named as chloride.
Step 3: Indicate the number of each atom in the molecule using prefixes. Below are the prefixes used in naming
molecular compounds.
Note that the prefix mono- is only used on the second atom.
Examples
1. CO - carbon monoxide
2. SCl3 - sulfur trichloride
3. CCl4 - carbon tetrachloride
Activity 2: Naming of Compounds
I.
II.
Write the chemical formulas for the following inorganic compounds.
A. Binary Ionic Compounds
1. Zinc chloride
__ZnCl2________________________________________
2. Barium oxide
_______________________________________________
3. Plumbic bromide
_______________________________________________
4. Iron (II) sulfide
_______________________________________________
5. Sodium hydride
_______________________________________________
6. Potassium iodide
_______________________________________________
B. Binary Covalent Compounds:
1. Boron triflouride
__BF3___________________________________________
2. Phosphorous pentoxide ________________________________________________
3. Dichlorinepentoxide
________________________________________________
4. Carbon tetrachloride
________________________________________________
5. Sulfur trioxide
________________________________________________
6. Nitrogen trioxide
________________________________________________
Write the chemical names of the following inorganic compounds.
A. Binary Ionic Compounds
1. CaS
__Calcium sulfide__________________________________
2. KCl
_________________________________________________
3. Al2O3
_________________________________________________
4. CuI2
_________________________________________________
5. SnO2
_________________________________________________
6. Na2S
_________________________________________________
B. Binary Covalent Compounds:
1. NO2
__Nitrogen dioxide________________________________
2. CBr4
________________________________________________
3. I2O3
________________________________________________
4. P4S10
________________________________________________
5. CCl
________________________________________________
6. N2S4
________________________________________________
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SCIENCE 9
A. Multiple Choice: Select the letter of the best answer from among the given choices. Shade your answer on
your answer sheet.
1. What kind of bond will result when two identical non-metallic atoms combine?
a. Ionic bond
c. Polar covalent bond
b. Metallic bond
d. Nonpolar covalent bond
2. Choose 2 elements that would likely form an ionic bond among the following elements: Li, Si, F, Ne
a. Li and Si
c. Ne and Si
b. Si and F
d. Li and F
3. How is the bond in Br2 different from the bond in MgF2?
a. The bond in Br2 is metallic while the bond in MgF2 is covalent.
b. The bond in Br2 is ionic while the bond in MgF2 is covalent.
c. The bond in Br2 is covalent while the bond in MgF2 is ionic.
d. There is no bond difference between the two.
4. How does ionic bonding take place?
a. Two non-metallic elements of different kinds form strong forces of attraction.
b. Two non-metallic element of the same kind form strong forces of attraction.
c. A non-metallic element like fluorine is attracted to a metallic element like sodium.
d. A metallic element like sodium transfers an electron to a non-metallic element like fluorine.
5. What kind of chemical bond will form between two oxygen atoms?
a. ionic bond
c. metallic bond
b. polar covalent bond
d. nonpolar covalent bond
6. It states that a compound, regardless of its method of synthesis or origin, has a fixed ratio of its
constituent atoms.
a. Law of definite proportion
c. Law of multiple proportion
b. Law of varying proportion
d. Law of conservation of mass
7. It is a group of elements that is well-known for its chemical inertness and stability.
a. Noble gases
c. Halogen gases
b. Lanthanide gases
d. Actinide gases
8. Which among the following Lewis electron-dot symbols is correct for carbon?
a.
c.
b.
d.
9. What particle is produced when the number of protons is greater than the number of electrons?
a. Cation
c. Anion
b. Neutral atom
d. Atom
10. Which is true when an atom loses electrons?
a. The atom becomes a positively charged particle.
b. The atom becomes a negatively charged particle.
c. The atom will have a neutral charge.
d. The atom can either have a positive or negative charge.
REFERENCES:
1. Quipper, 2021, Unit 6: Chemical Bonding, Retrieved from
https://link.quipper.com/en/organizations/5468b5f82294ee0802000169/curriculum#curriculum
2. Pinterest, Worksheet: Chemical Bonding, Retrieved from https://www.pinterest.ph/pin/648588783826208353/
3. Department of Education Science 9, Learner’s Module, Unit 2, Module 2: Chemical Bonding, pp. 112 – 113 and p.
126.
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