1. The Atom (4:00 min.)

2. Atoms

3. How do Atoms of different elements differ from each other?
p. 90
How do Atoms
of different elements
differ from each other?
There are over 118 different elements.
Each element has its own unique atoms.
Lets start with the simplest atom

4. All atoms are about the same size, but it’s what’s inside that counts.
Notice the helium
atom has two electrons, two neutrons
and two protons
Notice the hydrogen
atom has one electron
and one proton

5. 29 protons means that the atom
Atomic Number p. 91
The number of protons in the nucleus of an
atom is the Atomic Number of that atom.
29 protons means that the atom
also has 29 electrons.
29 protons in the nucleus of a copper atom

6. Use the periodic table on page 109 in your Textbook
to answer the following questions:
1. What is the atomic number of Boron?
2. What is the atomic number of Aluminum?
3. What is the atomic number of Neon?
4. What is the atomic number of Oxygen?
True or False (if the statement is false, give the correct answer)
5. The boron atom has 17 electrons in its orbit?
False (5 electrons)
6. Aluminum has 13 electrons in its orbit?
True
7. The number of protons is equal to the number of electrons?
8. Number of protons and neutrons are always the same?
True
False: protons and neutrons do
not have to be equal.

7. Isotopes p. 92-93 An atom that has the same number of protons
(same atomic number) as
another element, but has a different number of neutrons.
Heavier or lighter variations
of the same element.
Both atoms are “Carbon” atoms. One is heavier.
Can you guess which one?
Carbon – 12 or
Carbon – 14

8. Forces in Atoms p. 94
4 forces are at work holding the atom together

9. Gravitational force
Gravity is most easily observed in the behavior of large objects.
Inside the tiny nucleus of an atom, the effect of gravity is small compared
to the effects of the other three forces. Therefore, gravity is the
weakest of the four forces!!!

10. Electromagnetic force
Electromagnetic force
A force that combines the
effects of electrical charge
and magnetism. The
electromagnetic force can either
attract or repel the particles on
which it acts. Oppositely
charged particles attract each
other, while like particles
repel one another.
Electrons are kept in the orbit around the
nucleus by the electromagnetic force,
because the nucleus in the center of
the atom is positively charged and attracts
the negatively charged electrons.

11. Strong Force The strong forces and electromagnetic
Strong
Force
The strong forces oppose the electromagnetic force of repulsion between protons. Like ”glue” the strong force keeps the protons together to form the nucleus.
The strong forces and electromagnetic
forces both hold the atom together.

12. Weak force
Weak forces are important because they are responsible for stabilizing particles
through the process of radioactive decay, in which a neutron in the nucleus changes into a proton and an electron.

13. Obi-wan and Anakin understand the force.
Do you? Explain and illustrate with the work
-sheet your teacher is passing out!

14. Now, get to work or I’ll
have to use the force!!