Strategic Intervention Material in Grade 8 Science about determining the number of protons, electrons and neutrons of an atom.

1. Department of Education
Region III
Division of Zambales
GUISGUIS NATIONAL HIGH SCHOOL

2. This Strategic Intervention Material is designed to give you better
understanding on atomic and mass numbers.
There are basic activities that you will perform which involve
Mass Numbers. Activity exercises are prepared to let you master the skills
while assessment exercises are provided to help you master your learning.
Don’t forget to try working on the enrichment exercises for they are made
to challenge your thinking. Take notice of the reference card, it will provide
you carefully researched list of resources for your further reading.
Least Mastered Skill:
 Determining the number of protons, neutrons, and electrons in
a particular atom
Sub-Tasks:
1. Locate the atomic number in a periodic table
2. Identify the subatomic particles associated with mass number
3. Determine the number of neutrons from the mass number

3. Atoms of each element contain a characteristic number of pro-
tons. In fact, the number of protons determines what atom we are look-
ing at; the number of protons in an atom is called the atomic number. In
contrast, the number of neutrons for a given element can vary. Together,
the number of protons and the number of neutrons determine an element’s
mass number: mass number = protons + neutrons. If you want to calcu-
late how many neutrons an atom has, you can simply subtract the number
of protons, or atomic number, from the mass number.

4. Hi there, buddy! I’m Mr.. APE MAN to the rescue! I
will show you how to find the number of protons, electrons
and neutrons. Consider my APE MAN mnemonics below.
The challenge is for you to succeed every activity for
this session. I want you to earn a total of 100 points in order
to accomplish this challenge. Every correct answer in each
activity has corresponding points.
#

5. Can I have your number?
Direction: Find the atomic number of the enlarged elements from the periodic table.
Write your answer inside each star. Each item is worth 2 points .

6. 1 32
M A O T n o o r p t n c o e r e t l
4 PICS 1 WORD
Direction: Use the following pictures to identify the words
related to the topic. Use the jumbled letters as clues.
Each item is worth 5
points.

7. 2 BECOME 1...
Direction: Given the numbers of protons and neutrons,
identify the mass number of each element.
Write your answers on the third column.
Element Number of
Protons
Number of
Neutrons
Mass
Number
Oxygen 8 8
Chlorine 17 18
Sodium 11 12
Magnesium 12 12
Phosphorus 15 16
Get it all right and
get 10 points for this
task...

8. Name of Ele-
ment
Number of
Protons
Number of
Neutrons
Mass Num-
ber
Zinc 30 65
Potassium 19 30
Silver 47 108
Lead 82 207
Oxygen 8 16
Direction: Fill in the second column with the correct number of
neutrons of each element. Each item is worth 2 points + 1
point for the bonus question below.
How do you determine the number of
neutrons of an atom if mass and atomic
numbers are given?
#

9. or
Direction: On the blank before each number, write a
positive sign (+) if the statement is correct
and a negative sign (-) if it is wrong.
Each item is worth 2 points.
____ 1. The atomic number of an element is the
number of protons and neutrons in the
nucleus.
____ 2. All atoms have the same number of protons.
____ 3. Atomic number is the number of protons in
an atom.
____ 4. Mass number minus atomic number of an
element equals number of neutrons.
____ 5. Electrons and protons are associated with
the mass number of an element.
How are you bud-
dy? Looks like you
are doing great...

10. MY RIGHT CHOICE...
Direction: Choose the letter of the correct answer. Write your
answer on the space provided before each number.
____1. If sodium (Na) has 9 protons, how many electrons does it have?
A. 6 C. 8
B. 7 D. 9
____2. Calcium has a mass number of 40 and an atomic number of 20,
how many neutrons are in the atom?
A. 20 C. 40
B. 30 D. 50
____3. Fluorine has 9 protons and 10 neutrons, what is its mass num-
ber?
A. 9 C. 1
B. 10 D. 19
____4. Oxygen atom has an atomic number of 8, how many electrons
does it have?
A. 16 C. 32
B. 8 D. 18
____5. Chlorine has a mass number of 35 and 18 neutrons, how many
protons does it have?
A. 18 C. 17
B. 35 D. 53
Do it buddy to get 2
points in each item.
Good luck!

11. You complete me…
Direction: Fill in the table with the atomic information of the
elements. Don’t forget to use the APE MAN
mnemonics for your convenience.
Element’s
Name
Number of
Protons
Number of
Electrons
Number of
Neutrons
Atomic
Number
Mass
Number
Iron 26 56
Carbon 6 6
Chromium 24 52
Good luck buddy!
18 points is at
stake...

12. GUESS WHAT?
Direction: Identify the element being described by Mr. APE MAN.
Choose your answers on the right and write the name of
the element on the sheet provided. Every correct answer is
worth 2 points.
Lastly, what element is a
good conductor of heat
and electricity? It has 13
electrons and 14 neu-
trons.
How about the ele-
ment with 10 neutrons and
10 protons which is used
for lights, lasers, and TV
tubes?
This element has 8 neutrons
and 8 electrons. It is com-
pletely essential for human
survival. What is it?
Answer Sheet
1.
2.
3.

13. SIMPLE AS ABC…
Direction: Complete the crossword by filling in a word that fits the
given clues.
Hi buddy! Mr. APE
MAN is just here to help
you answer the puzzle.
Good luck!
5.
M
1.
T2.
RS4.
T
L3. O
S
2 points
1. _________ is the number of 2. ________ in an atom
which is also equal to the number of 3. __________.
4. __________ minus atomic number is equal to the
number of 5. ________.

14. Try to read further...
G8 Science Learner’s Material pp. 203-205
G8 Science Teacher’s Guide pp. 140-143
Villamar Jr., Rufino A., Chemistry, Quezon City:
St. Bernadette Publishing House Corporation.
C2004. pp 42-45
Angeles, Delfiin C., Science Vistas 8, Makati
City:
Salesiana Books by Don Bosco Press, Inc.
C2013. pp 261-264

15. My Score
________Hi buddy! How well did
you learn from this
lesson?

16. Activity
Card
1
1. 20
2. 28
3. 51
4. 17
5. 36
Activity
card 2
1. Atom
2. Proton
3. electron
Activity
card 3
1. 16
2. 35
3. 23
4. 24
5. 31
Activity
card 4
1. 35
2. 11
3. 61
4. 125
5. 8

17. ASSESSMENT
CARD 1
1. -
2. -
3. +
4. +
5. -
ASSESSMENT CARD 3
Iron 26 26 30 26 56
Car-
bon
6 6 6 6 12
Chro-
mium
24 24 28 24 52
ASSESSMENT
CARD 2
1. D
2. A
3. D
4. B
5. C

18. ENRICHMENT CARD 1
1. oxygen
2. Neon
3. aluminum
ENRICHMENT CARD 2
1. atomic number
2. Protons
3. Electrons
4. Mass number
5. neutrons

19. THANK YOU!
This Strategic Intervention Material in Science 8 is made by
JEANNE M. MACABUNGA
Teacher II
Guisguis National High School
Approved:
JULITA M. VALDEZ
Principal II