Atoms, Elements, and The Periodic Table

1. Atoms, Elements, and The Periodic Table Structure of matter A. What is Matter? Matter is anything that has mass and takes up space (Volume) B. What isn’t Matter? Light and Heat do not take up space nor do they have a mass.

2. Atoms, Elements, and The Periodic Table Democritus (460 B.C – 370 B.C.) A Greek Philosopher C. What makes up matter? Early Ideas: __________________________________________________________________ ▫ Believed the universe to be made of ___________ and _______ were so small they could not be broken down any more ▫ He Called the tiny pieces _______ ▫ _____ in Greek means: “________________” empty space tiny bits “Atoms” Atom Cannot be divided

3. Atoms, Elements, and The Periodic Table AntoineLavoisier(la VWAH see ay) The father of Modern Chemistry C. What makes up matter? _______________________ A French Chemist (1743-1794) Known as ___________________________ Showed through experiments, that matter has the same ___________and _____ a change of state or form (ex.___________) From his experiments came ____________________________ ▫ Matter is neither __________________ ▫ __________________ from one form to another mass before after fire and rust The law of conservation of matter Very Important! You will see this on CRT’s so HIGHLIGHT created or destroyed Matter only changes

4. Atoms, Elements, and The Periodic Table John Dalton 1766–1844 modern atomic Atomic Theory of Matter Composed of very small particles called atoms D. Models of the Atom _______________ An English Schoolteacher and chemist____________ Proposed the first ______________ theory The _______________________ contained five parts 1. All matter is __________________________________ _____________________________________________ 2. All ______ of a given ________ are __________ 3. Atoms cannot be _____________________________ 4. In chemical reactions, _________________________ ___________________________________________ 5. In chemical reactions, atoms combine with each other in ___________________________to form combined atoms Atoms Element Identical created, destroyed, or subdivided atoms combine with or separate from other atoms simple, whole-number ratios

5. Atoms, Elements, and The Periodic Table J. J. Thomson British Scientist 1856 – 1940 Cathode Ray Tube D. Models of the Atom _______________ _____________________________ Conducted experiments using a _________________ From his experiments he discovered _______ contained __________________________ ▫ The negative charged particle is called an ________ ◦ An _________ is ______ the mass of the _______ atom, the _________ atom. ◦ Thomson’s model of the atom had electrons spread throughout a ____________________. Like _____________________________. Atoms Negatively Charged Particles Electron Electron 1/1,837 Smallest Hydrogen ball of positive charge Chocolate chips in cookie dough

6. Atoms, Elements, and The Periodic Table Ernest Rutherford New Zealander Physicist Father of Nuclear Physics J. J. Thomson D. Models of the Atom _______________ An _______________________1871 – 1937 Known as the ______________________ Was a student of _____________ From experiments with X-Rays, he discovered the atom contained_______________________. These were called ________ He also concluded the _____________ was found in the _________________. The center was called ____________ Positive charged particles Protons positive charge center of the atom The Nucleus

7. Atoms, Elements, and The Periodic Table Niels Bohr Danish Physicist electrons Energy levels D. Models of the Atom _________ A _______________ 1885 – 1962 Arranged __________ in atoms according to ____________ ▫ _________________ is closest to the nucleus and contains only __________ ▫ __________________ are further from the nucleus and contain _____________ ▫ Many scientist thought the electrons traveled around the nucleus in orbits like planets around the sun. Later this was shown to be incorrect Lowest energy level 2 electrons Higher energy levels more electrons