2. ATOMIC THEORY Philosophical Idea to Scientific Theory Chapter 3 Section 1

3. Who? ________________ 400B.C. A _________ philosopher Believed that ________were the smallest particles of matter and that different atoms comprised different materials.

4. Atom is from the Greek word_______, meaning, indivisible. Purely _________ ideas at this point.

5. Who? ______________ (300 B.C.) Greek philosopher who ________ Democritus’ atom. Proposed that ___________ Called contiuous matter, _______

6. Who? ___________&___________ 1600 Rejected ___________ in published articles. Still did not have______ that atoms existed.

7. Who? ____________1700’s The “___________” One of the first scientists to use _______________ to support his ___________. Proposed the Law of Conservation of Mass in 1782.

8. Law of ___________of Mass Matter cannot be created or destroyed______________ ____. Mass of ________= mass of_____________.

9. Who? ________________ late 1700’s Observed that specific substances (___________) always contain the same elements in the same____________ This is known as the _________________________. Ex. NaCl always consists of:

10. WHO? ________________ and _____________ 1790’s Law of ________Proportions When _________________of the same 2 elements exist, the masses of the second element combined with a certain mass of the first is always a _______ ______________________.

11. MULTIPLE PROPORTIONS Example: Mass of Oxygen Mass of Nitrogen Ratio of O/N NO16.00 g14.01 g16.00/14.01= 1.14 NO 2 32.00 g14.01 g32.00/14.01 =2.28

12. WHO? _______________ 1800’s Democritus’ atom Law of conservation of mass Law of definite proportions Law of multiple proportions Proposed his _____________in 1808 based on the following:

13. 5 Principles of Dalton’s Atomic Theory 1.All matter is composed of extremely small particles called atoms which cannot be___________, ________ or ___________.

14. 5 Principles of Dalton’s Atomic Theory 2.Atoms of a given element are ____________in their physical and chemical properties. 3.Atoms of different elements___________ in their physical and chemical properties.

15. 5 Principles of Dalton’s Atomic Theory 4. Atoms of different ____________combine in simple, _____________ to form_____________.

16. 5 Principles of Dalton’s Atomic Theory 5. In chemical reactions, atoms are __________,__________, or_________, but never created destroyed or changed.

17. CURRENT ATOMIC THEORY The first principle of Dalton’s atomic theory has been________. Atoms can be _______________. Atoms can be subdivided into ________particles:  ________ How were each of these discovered?

18. ADDITIONAL SUBATOMIC PARTICLES Who discovered the neutron? What is a quark? Find the names and characteristics of the quarks.