Atomic Structure Notes History of the Atom 1808
- Slides: 12
Atomic Structure Notes
History of the Atom • 1808 John Dalton – Matter made of tiny particles called atoms • 1897 Joseph Thomson – Discovery of electrons using cathode rays • 1909 Robert Millikan – Discovery of negative charge on electrons • 1911 Ernest Rutherford – Discovery of nucleus, lots of open space in an atom • 1914 Neils Bohr – Electrons orbit the nucleus in different shells • Modern Atomic Theory
• Atom – The smallest particle of an element that retains the chemical properties of that element. • Nucleus – Positively charged center of the atom that consisting of protons and neutrons that contain nearly all the atoms mass with a very low volume.
• Proton – Subatomic particle of the nucleus that has a positive charge. • Neutron – Subatomic particle of the nucleus that has a neutral charge. • Electron – Subatomic particle outside the nucleus that has a negative charge.
Proton Neutron Nucleus Electron - Electron Region + N N +
Subatomic Particles Name Charge Weight Proton + 1 amu Neutron N 1 amu Electron - . 0005 amu
• Atomic Mass Unit – 1 amu, exactly 1/12 the mass of a carbon -12 atom. • Average Atomic Mass – The weighted average of the atomic masses of the naturally occurring isotopes of an element. • Isotopes – Atoms of the same element that have different masses.
• Atomic Number – The number of protons in the nucleus of each atom of that element. Used to identify elements. • Mass Number – The total number of protons and neutrons in the nucleus of an atom. Mass # = Protons + Neutrons = Mass # - Protons
Mass Number, Protons, Neutrons and Electrons Element Protons Neutrons Electrons Mass # Hydrogen 1 0 1 1 Carbon-12 6 6 6 12 Carbon-14 6 8 6 14 Oxygen-16 8 8 8 16 Oxygen-17 8 9 8 17
Hyphenated Notation Carbon – 14 Element Mass #
Atomic Number and Mass Notation 14 6 Mass # C Atomic # Symbol
Relation of atomic mass and molar mass Carbon-12 • Atomic mass = 12. 011 amu • Molar mass = 12. 011 g/mol • The only difference is the units
- Number of protons in hydrogen
- 1808 atomic model
- Atomic model 1808
- The structure of the atom section 2 defining the atom
- Ab 1808
- Ccc 1808
- Third of may 1808 meaning
- John dalton 1808
- Napoleon crossing the alps era
- The death of marat meaning
- Third of may 1808 meaning
- La imagen del átomo expuesta por dalton
- Is atomic mass and relative atomic mass the same