LESSON PLAN IN PHYSICAL SCIENCE GRADE 12
October 28, 2019
7:45 – 8:45 (Smartness) 8:45 – 9:45 (Intelligence) 10:00 – 11:00 (Greatness)
11:00 – 12:00 (Excellence) 1:00 – 2:00 (Brilliance) 2:00 – 3:00 (Brightness)
I. OBJECTIVES:
A. CONTENT STANDARDS:
The Formation Of The Elements During The Big Bang And During Stellar
Evolution
B. PERFORMANCE STANDARDS
make a creative representation of the historical development of the atom or the
chemical element in a timeline
C. LEARNING COMPETENCIES
give evidence for and explain the formation of the light elements in the Big Bang
theory (S11/12PS-IIIa-1)
II. CONTENT
How the elements found in the universe were formed
III. LEARNING RESOURCES.
Physical Science Teaching Guide, page 25
IV. PROCEDURE:
A. BEFORE THE LESSON
1. Elicit
a. Ask the students about their belief on the origins of the universe. Then
briefly define cosmology as the study how the universe began
2. Engage
a. Give the outline of the lesson for the day
B. DURING THE LESSON
1. Explore
a. Perform the balloon inflation activity to model cosmic
in1flation. Group the students into 5. Let the groups answer
the following questions
after performing the activity:
- Why do the stickers appear to be moving away from each
other?
- Are the stickers moving across the balloon?
- Do the stickers themselves grow in size?
2. Explain
- The different groups explains the results of the activity using
PowerPoint and the answers to the different questions.
3. Elaborate
a. Relate the results of the activity to the discussion of the Big Bang
Model
b. Discuss the key stages of the Big Bang Model
- The universe may have begun as an infinitely hot and dense initial
singularity, a point with all of space, time, matter and energy. This
means that there was no where, when or what. There is no space
around the singularity – just nothingness.
- All of it then began to rapidly expand in a process known as
inflation. Space itself expanded faster than the speed of light. In
this still hot and dense mass of the universe, pairs of matter and
antimatter (quarks and antiquarks) were formed from energy, but
these pairs cancelled each other back into energy (annihilation).
- The universe cooled down as it expanded. An excess of matter
(electrons, protons, neutrons and other particles) somehow came
to be in a highly energetic “plasma soup.” Photons (light particles)
were being scattered everywhere in this “soup”. Protons and
neutrons came together to form different types of nuclei by
nucleosynthesis or nuclear fusion.
- Much later on, electrons started to bind to ionized protons and
nuclei forming neutral atoms in a process called recombination.
The bound particles no longer scattered photons so light and
energy moved freely across space. The period was hence known
as the “dark ages”.
- Gravity caused these atoms to collapse onto one another to form
stars and galaxies and eventually, other matter. This still happens
until today. Space also continues to expand at an accelerating
rate, thus increasing the distance between the matters inside it.
- Discuss redshift – the observation of the stretching of the light
which suggests that other galaxies are moving away farther from
our position. Redshift is the first piece of evidence in the Big Bang
Model
- Discuss nucleosynthesis and how free protons and neutrons
would routinely combine and separate from each other due to the
high energies at the time. Present the diagram that shows the
most significant reactions that occurred. Discuss the reactions by
balancing proton and neutron count, given the compositions of the
nuclei
- Point out that due to the rapid cooling due to expansion,
nucleosynthesis ground to a halt about three minutes after the Big
Bang occurred. This left us with mostly H isotopes (p, D and T),
He isotopes and a very tiny bit of other elements like Li. The
relative abundance of He and H did not change much until today.
- Discuss how the relative abundance of light elements in the
universe is the second piece of evidence to prove that the Big
Bang occurred. Through measurements, we find that around 24%
of the universe’s ordinary matter is currently comprised of helium,
about 74% hydrogen, and 2% of other elements. These figures
only make sense if nucleosynthesis in the Big Bang model actually
occurred since no chemical process significantly changes these
percentages
- Discuss a third part of evidence for the Big Bang model: cosmic
microwave background, or the energy (thermal radiation) that was
left as a result of recombination. Atoms became neutral due to the
binding of nuclei and electrons. The remaining radiation then
began to scatter. This is seen by scientists as a faint microwave
glow not emitted by any object in space
- Discuss the different nuclear reactions that occur during the first
moments of the Big Bang.
- Share with learners a video by Youtube animator Kurzgesagt.
www.youtube.com/watch? v=wNDGgL73ihY. Inform learners that
it can serve as a simple summary of the lesson that they may refer
to as a more detailed discussion of the BBT and other
cosmological theories are discussed later on.
C. AFTER THE LESSON
1. Evaluate
Additional Exercises (sample questions for Written Evaluation):
a. Arrange the stages of the Big Bang Theory: recombination, inflation, Big Bang
singularity, nucleosynthesis.
b. Given the composition of each nucleus, complete the nucleosynthesis reactions
below:
c. Which of these is true about the Big Bang model?
- The singularity is an established, well-defined part of the model.
- Cosmic expansion stopped at some point in time.
- Part of its proof is the amounts of H and He we have in the universe today.
- The Big Bang was a big explosion that threw matter into many different
directions.
d. Using one to two sentences each, explain the three pieces of evidence presented
for the Big Bang Theory: a. Redshift b. Relative abundance c. Cosmic
microwave background
2. Extend
Have groups of learners research the Steady State Theory, which is the alternate
scientific cosmological theory proposed at the time. In their output, they must:
a. Present the features of the Steady State Theory
b. Compare and contrast Steady State Theory to the Big Bang
c. Discuss the evidence that led to the Steady State Theory being discarded.
Learners may present their research in the form of a poster, PowerPoint
presentation, an essay, video, or infographic.
V. REMARKS
VII. REFLECTIONS
Prepared:
LESTER P. BERNARDINO, M.Ed
Master Teacher I
