I.
II.
Activity No. 2: Crossword Puzzle: Atomic Models in Focus (15 minutes)
Objective(s):
1. Demonstrate understanding of scientific models and their importance in
understanding atomic structure.
2. Summarize key concepts and historical evolution of atomic models.
III. Materials Needed:
1. Pen/Pencil
2. Worksheet
IV. Instructions:
1. The crossword puzzle contains terms related to atoms and atomic models that they
have learned about in previous lessons. Fill in the puzzle with the correct terms
based on the provided descriptions.
2. Pay attention to the number of letters in each word and the intersecting letters of
the adjacent words to determine the correct answers.
Across:
4. Atomic model where electrons don't
move around the nucleus in orbits.
Electrons exist in specific energy levels
as a cloud.
8. Electrons reside in orbits. They move
between each shell when gaining or
losing energy.
9. Negatively charged particles
10. Building block of matter that cannot
be broken apart using any chemical
means
Down:
1. An atom is made out of a sphere of
positive charges with negatively charged
electron embedded in it.
2. Subatomic particle with a neutral charge
3. A tangible model.
4. Matter is made of small indivisible
atoms.
5. Most of the mass is concentrated in the
center of atom. This tiny, dense,
positively charged core called a nucleus.
6. Positively charged particles
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