Name ____________________________________________________ Date _________________ Class _______
Understanding Atomic Structure
Lesson 1 – The Atom
1. What three subatomic particles make up atoms?
2. By what two basic traits can you categorize
atoms?
7. What is the charge of a neutron? _______
What is the mass of a neutron? (include units)
_____________
8. What particles make up the nucleus?
9. Describe an atomic nucleus.
3. What is charge?
4. What is mass?
5. What is the charge of a proton? _________
What is the mass of a proton? (include units)
_____________
6. What is the charge of an electron? __________
What do we consider the mass of an electron to
be?________
10. Where are electrons found?
11. What determines an atom’s atomic number?
12. What is an element?
13. What do chemists use to organize the elements?
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Lesson 2 – Atomic Number and Mass Number
1. What is an atom?
2. Why can protons be considered the most
important part of an atom?
7. Describe two ways that neutrons are similar to
protons.
8. How are protons and neutrons different?
3. What determines an atom’s atomic number?
4. What does amu stand for?
5. Why do we use amu when talking about the
mass of atoms and molecules?
9. What are isotopes?
10. Do isotopes of the same element react the same
in chemical reactions?
11. Do isotopes of the same element react the same
in nuclear reactions?
6. Name two properties of the atomic nucleus.
12. Show the nuclear symbols for the three isotopes
of carbon.
15. Why is the electron cloud considered to be
mostly empty space?
13. In a nuclear symbol, where is the atomic number
located?
What does this number tell us?
16. What key role do electrons play?
14. In a nuclear symbol, where is the mass number
located?
What does this number tell us?
17. How does the charge of an electron relate to the
charge of a proton?
18. Why do we say that electrons have no mass,
even though they actually do?
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Lesson 3 – Early Atomic Theory: Dalton, Thomson, Rutherford, Millikan
1. Who disproved Aristotle’s theory of matter and
supported Democtitus’ idea of the indivisible
atom?
5. How did this discovery prove part of the original
Atomic Theory wrong?
2. List four things that this person declared about
atoms.
6. What was the resulting atomic model called?
7. Draw a picture of this model.
3. What piece of equipment did JJ Thomson use?
4. Describe two properties of the green beam that
he studied.
8. Describe an alpha particle.
9. What did Rutherford shoot alpha particles at?
10. Explain what he expected to happen vs what
really did happen.
11. How did Rutherford describe the nucleus that he
had discovered?
12. Draw a picture of this nuclear model of the atom
Don’t worry about Millikan. Interesting stuff, but not crucial to know.
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Lesson 4 - Isotopes and Average Atomic Mass
1. What two subatomic particles contribute to the
mass of an atom?
7. What does it mean to say that some water is
“heavy water?”
2. What are isotopes?
8. What units are used to define atomic mass?
3. Most hydrogen atoms have how many neutrons?
__________ What is this isotope called?
___________________________
9. How is the atomic mass that is written on the
periodic table determined?
4. How is deuterium different from protium?
5. What is tritium?
6. How come protium, deuterium and tritium can
all be hydrogen, even though they have different
masses?
10. What are the two major isotopes of lithium?
11. Why is lithium’s average atomic mass closer to
7 than it is to 6?