1. 815

2. Recognize that all matter consists of atoms. Key concepts/skills: Level 1: Define key vocabulary. Describe the basic structure of an atom. Level 2: Explain Dalton's Atomic Theory. Describe how all matter is made up of atoms. Level 3: Calculate mass number, atomic number, number of protons, neutrons or electrons. Explain how the same element can have different isotopes.

3. Key vocabulary: matter atom mass number mass proton atomic number volume neutron isotope atomic theory energy levels

4. I.Dalton’s Atomic theory A.1803 John Dalton came up with his atomic theory 1.All substances are made up of atoms and atoms cannot be divided. 2.Atoms of the same element are exactly alike. 3.Atoms join with other atoms to make new substances.

5. Recognize that all matter consists of atoms. A.Now we know (Modern atomic theory) 1. All matter is made up of atoms 2. Atoms can be divided (fission) 3. Atoms of the same element can be different (isotopes) different versions of the same element 4. Atoms of different elements are different 5. Atoms combine to form compounds

6. Recognize that all matter consists of atoms. II. Structure of the atom A.Nucleus 1.Protons - + charges particles make up the nucleus 2.Neutrons – neutral particles make up the nucleus B.Electrons 1.Negatively charged particles that orbit around the nucleus

7. III. Drawing an Atom A.Atomic number – the least of the two numbers/ tells the number of protons the atom has B.Mass number - the greatest of the two numbers/ is the sum of protons plus neutrons 1.If you subtract the atomic number from the mass number you get the number of neutrons in the atom Recognize that all matter consists of atoms.

8. A.Drawing electrons 1.Electrons travel in definite energy levels 2.1 st level holds 2 e-, 2 nd level holds 8 e-, 3 rd level holds 18 e- 3.When drawings electron, you fill 1 st with 2 e- then fill the second and so on

9. Other Related Terms

10. Isotopes 1.Isotopes are different version of the same element 2. The only thing that changes is the number of NEUTRONS

11. Atoms are Too small to see!