1. Chapter 3
Atomic structure

2. Student check In your own words what do you think the
“Big Bang Theory” is?

3. Structure of the Atom There are two regions The __________________
________ and ________
Positive charge/ protons
Almost all the mass is found in the Nucleus
2. ___________________________- Most of the volume of an atom.The region where the electron can be found

4. Counting the Pieces ___________________ Number = number of protons
# of protons determines kind of atom
the same as the number of electrons in the neutral atom
_____________________ Number = the number of protons + neutrons
All the things with mass

5. Student What do you know about the atom?
What do you know about the nucleus?

6. Isotopes Dalton was wrong.
Atoms of the same element can have different numbers of ______________
different ___________________
called __________________

7. Student What is the mass number?
What two parts of the atom make up most of the mass of an atom?

8. X Symbols ______ number ______ number
Contain the symbol of the element, the mass number and the atomic number
______
number X
______
number

9. F Symbols 19 9 Find the number of protons number of neutrons
number of electrons
Atomic number
Mass Number 19 F 9

10. Br Symbols 80 35 Find the number of protons number of neutrons
number of electrons
Atomic number
Mass Number 80 Br 35

11. Symbols
if an element has an atomic number of 34 and a mass number of 78 what is the
number of protons
number of neutrons
number of electrons
Complete symbol

12. Symbols if an element has 91 protons and 140 neutrons what is the
Atomic number
Mass number
number of electrons
Complete symbol

13. Symbols if an element has 78 electrons and 117 neutrons what is the
Atomic number
Mass number
number of protons
Complete symbol

14. Naming Isotopes Put the mass number after the name of the element
carbon- 12
carbon -14
uranium-235

15. Student What is the. What is an isotope?
Atomic number
Mass number
number of protons
Complete symbol
What is an isotope?
What questions do you still have?