1. Atomic Structure and Modelling

2. General Structure central nucleus containing protons and neutrons, tightly packed central nucleus containing protons and neutrons, tightly packed fast moving electrons move around nucleus in a cloud fast moving electrons move around nucleus in a cloud size of an atom (radius) depends on size of ______________ size of an atom (radius) depends on size of ______________ mass of the atom is concentrated in the _________ mass of the atom is concentrated in the _________

3. General Structure

4. History of Atomic Models 1.___________ (400 B.C.) -Greek philosopher -thought matter was made up of smaller particles he called ______

5. Atomic Theory 2. ___________ (1766-1844) -English chemistry teacher who studied the ratios of elements in chemical reactions -developed a theory about atoms

6. Dalton’s Atomic Theory 1.All matter consists of _______. -atoms of an element cannot be cut smaller and cannot be created or destroyed 2.All the ______ of one element are ________ in mass and other properties and are ________ from atoms of any other element. -Ex. all oxygen atoms have same mass and properties which are different than any other element 3. Atoms of one element cannot be __________ into atoms of another element.

7. Dalton’s Atomic Theory cont’d 4.Compounds are the chemical combination of two or more elements in a __________. - Ex. the compound water (H 2 O) always has a ratio of hydrogen to oxygen that is 2:1 (2 H for every 1 O) - Ex. the compound water (H 2 O) always has a ratio of hydrogen to oxygen that is 2:1 (2 H for every 1 O) Was Dalton correct?? Were any points of his theory wrong??

8. Developing Atomic Models 3. _____________ (1856-1940) -English physicist who discovered the electron -proposed ___________ model, postively charged mass with electrons distributed all over

9. More Models 4. ______________ (1871-1937) -English scientist -proved that atom is mostly _____________ with mass concentrated in small, central, positively charged middle (__________)

10. More Models 5.____________ (1885-1962) -Danish physicist -thought that electrons move around nucleus in ______ __________ (like planets orbiting the sun) -paths (or orbits) farther away from the nucleus have ____________________

11. Dalton (1807) Thomson (1897) - Cannot be broken into smaller pieces - Solid - Small - Raisin bun model - Positive mass with electrons embedded - Neutral atom Rutherford (1911) Bohr (1885) - Nuclease w/ protons - “Empty space w/ electrons” -Planetary model - Protons/neutrons in the middle (nucleus) - Electrons in energy levels orbits around nucleus