Power point presentation for Science 9, Second quarter.

1. PERCENTAGE
COMPOSITION
Prepared by: Catherine C. Dela Cruz
COT 1
Science 9
MELC Code: S9MT-IIj-20

2. IONIC BONDING

4. What are the ingredients of
bread?

5. Activity 1: Pair me!
The following are the ingredients in
making a bread. Pair the picture with
the correct name of the ingredients

6. Activity 1: Pair me!
Questions:
1. Can you make a bread if the ingredients
are not complete?
2. Did you use measurement in each
ingredient?
3. How many percent of the bread are water?
How about the sugar?

7. In mathematics, a percentage is a number or
ratio that can be expressed as a fraction of
100. If we have to calculate percent of a
number, divide the number by the whole and
multiply by 100. Hence, the percentage
means, a part per hundred. The word per cent
means per 100. It is represented by the
symbol “%”.
The formula is percentage= part/ whole x 100.

8. IONIC BONDING
K. Define the percentage composition of a
compound;
U. Understand that the amount of
substance intake can be monitored with
the use of percentage composition.; and
D. Calculate the percentage composition
of a compound given its chemical formula

10. PERCENTAGE COMPOSITION OF THE COMPOUND
-The mass of each element in a compound compare to the
entire mass of the compound multiplied by 100 percent .
Formula: %mass of element =
mass of element in the compound / mass of the compound x 100%

11. Example: CH4
Molar mass
C = 1 x 12.01g/mol = 12.01g/mol
H = 4x 1.01g/mol = 4.04g/mol__
16.05g/mol
Percentage composition of H Percentage composition of O
% mass of H = 4.04g/mol /16.05 g/mol x 100 % mass of C = 12.01g/mol / 16.05g/mol x 100
= 25.17 % = 74.83 %

12. ACTIVITY 2: IT’S GROCERY TIME!

13. Materials: Grocery item containers or packages, Internet,
cellphone, manila paper, pentel pen
Procedure:
1. Get two grocery items from the basket.
2. List the substances written as content or ingredients on the
label. Choose one substance from each type of grocery item
3. Research from internet the chemical formula of substance in
your list.
4. Compute the percentage composition of the substances you
have listed.

14. Guide Question:
1.Based on the activity, what food do you
regularly consume which give your body
a lot of carbon and sodium?
2.How important is knowing the
percentage composition of every
ingredients in choosing the best grocery
items?
3.In what other ways can you make use of
the concept of percentage composition?

17. Group Presentation

18. Why is it significant to read nutrition
labels percentage composition of
products?
- It shows you some key nutrients that
impact your health. You can use the label
to support your dietary needs and look for
the food that contains more nutrients.

19. Knowledge about percentage composition is very
useful in choosing the best item like food fertilizer,
food and other goods that we use everyday.in terms of
product development, percentage composition will
indicate the correct amount of substances needed in
order to produce the expected amount. For example, if
the manufacturing company wants to produce resin, it
will not be able to do it it does not know the correct
percentage of every component needed to form resin.

20. Ionic bonding involves cation (positive charge ion) and
anion (negative charge ion). It is a type of bonding by
transfer of electrons between metal and non-metal.
Typically, a metal loses an electron and becomes a positive
ion called cation while anion is formed when a non-metal
gains electron. They both achieve a more stable electronic
configuration through this exchange. Take note that Not all
metal-nonmetal combinations will result in an ionic
bond. Only those with electronegativity difference of
more than 1.9 will result to an ionic bond.

21. Using the ingredients of bread, namely the salt and
sugar. Calculate the percentage composition of
each element in the compound of salt (NaCl) and
sugar (C6H12O)
1. Salt
2. Sugar

22. Look for the products in your home and look at
the ingredients of the products. Choose two (2)
ingredients and search on the internet for its
chemical formula. After which, calculate the
percentage composition of the compound. Write
your answers on a 1 whole sheet of paper.