Electrons and Energy Levels
I.
Electrons are the negatively charged particles of an atom. All of
the electrons of an atom create a negative charge that balances
the positive charge of the protons in the atomic nucleus. Electrons
are extremely small compared to all of the other parts of the atom.
1) What are 3 basic things we need to know about electrons?
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II.
Electrons are located in clouds that surround the nucleus of an
atom. These clouds are specific distances away from the
nucleus. These clouds are organized into shells or energy levels.
2) What are electrons located in the atom?
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3) What are 2 things that describe atomic clouds?
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III.
Because electrons move so quickly, it is impossible to see where
they are at a specific moment in time. Electrons zip around in any
direction (upwards, downwards, or sidewards), but they stay in
their shell. Those shells, energy levels or orbitals, have specific
distances from the nucleus.
4) Do electrons revolve around the nucleus OR do they have a
different kind of movement? How?
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5) Why is it impossible to see where they are at a specific
moment in time?
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6) Examine the image: What is an orbital?
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7) What is an energy level?
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8) Which energy level is higher n=1 or n=4?
IV.
After years of experiments, scientists discovered specific areas
where electrons are likely to be found. The overall shape of the
shells (or energy levels) changes depending on how many
electrons an element has. The higher the atomic number, the more
shells and electrons an atom will have.
9) What determines the overall shape of the
shells in an atom?
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10) Which atom has more shells?
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V.
According to Bohr's atomic model, electrons revolve in fixed paths around
the nucleus . He called these paths “shells” or energy levels. Shells or
energy levels are represented by small n.
The first shell or energy level is represented by n = 1 or K
The second shell or energy level is represented by n = 2 or L
The third shell or energy level is represented by n = 3 or M
The 4th shell or energy level is represented by n = 4 or N
The 5th shell or energy level is represented by n = 5 or O
The 6th shell or energy level is represented by n = 6 or P
The 7th shell or energy level is represented by n = 7 or Q
VI.
According to Bohr, an electron can jump, suddenly, between energy levels
by absorbing or emitting a photon (light particle) with a precise wavelength.
Photons allow the electrons to move between energy states. When an
electron is hit by a photon of light, it absorbs the quanta of energy the
photon was carrying and moves to a higher energy state. Also, an electron
can emit a photon of energy and move down to a lower energy level.
11) How are energy levels represented in Bohr’s model?
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12) How is the first energy level represented?
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13) How is the 4th energy level represented?
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14) According to Bohr’s theory of electrons, what allows electrons to
jump from one energy level to another?
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15) What happens when a photon hits an electron?
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16) How does an electron move down to a lower energy level?
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17) What is a photon?
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