Chapter 3 Notes
Anion
A negatively charged ion.
Cation
A positively charged ion.
Electron Cloud Model
A sphere containing a nucleus, and an electron cloud.
Rutherford Model
A sphere showing the path of an electron and a nucleus.
Bohr Model
A sphere with a nucleus, path of an election,and rings.
Dalton's Atomic Theory (Part 1)
All matter is composed of extremely small particles called atoms.
Thomson Model
Also known as the "Plum Pudding Model", is a sphere with a positive charge throughout containing negatively charged particles called elections.
Geiger and Marsden
Assumed mass and charge were uniformly distributed throughout atoms.
Dalton's Atomic Theory (Part 3)
Atoms cannot be subdivided, created, or destroyed.
Dalton's Atomic Theory (Part 2)
Atoms of a given element are identical in size, mass,and other properties; atoms of different elements differ in size, mass, and other properties.
Dalton's Atomic Theory (Part 4)
Atoms of different elements combine in simple whole number ratios to form chemical compounds.
Millikan
Believed negative electrons were spread evenly throughout the positive charge of the rest of the atom.
Dalton
Believed the atom was indestructible and contained nothing.
Thomspn
Concluded all cathode rays are composed of negatively charged particles called electrons. (Discovered the electron)
Chadwick
Confirmed the existence of neutrons, which have no charge.
Schrodinger
Developed mathematical equations to describe the motion of electrons in atoms.
Democritus
Discovered the atom.
Rutherford
Discovered the volume of a nucleus was very small compared with the total volume of an atom (if the nucleus were the size of a marble, then the atom would be about the size of a football field.)
1926
Erwin Schrodinger develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model.
1923
French physicist Louis de Broglie proposes that moving particles like electrons have some properties of waves. Within a few years, evidence supports the idea.
1904
Hantaro Nagaoka, a Japanese physicist, suggests that an atom has a central nucleus. Electrons move in orbits like the the rings around Saturn.
Isotope
Has the same atomic number, and a different number of neutrons.
1913
In Niels Bohr's model, the electron moves in a circular orbit at fixed distances from the nucleus.
Dalton's Atomic Theory (Part 5)
In chemical reactions, atoms are combined, separated, or rearranged.
1897
J.J. Thomson, a British scientist, discovers the electron. This later leads to his "plum pudding model".
1932
James Chadwich, an English physicist, confirms the existence of neutrons, which have no charge. Atomic nuclei contain neutrons and positively charged protons.
1803
John Dalton pictures atoms as tiny, indestructible particles, with no internal structure.
1911
New Zealand Physicist Earnest Rutherford finds that an atom has a small, dense, positively charged nucleus. Electrons move all around the nucleus.
Goldstein
Predicted the existence of protons.
Bohr
Proposed electrons surround the positively charged nucleus.
Broglie
Proposed moving particles, like electrons, had some properties of waves.
Mole
SI base unit used to measure amount.
Nagaoka
Suggested an atom has a central nucleus.
Electron
Symbol: e- Relative Charge: 1- Relative Mass: 1/1840 Actual Mass: 9.11 x 10_-28
Neutron
Symbol: no Relative Charge: 0 Relative Mass: 1 Actual Mass: 1.67 x 10_-24
Proton
Symbol: p+ Relative Charge: 1+ Relative Mass: 1 Actual Mass: 1.67 x 10_-24
Atom
The smallest unit of an element.
Dalton Model
Tiny solid sphere with nothing inside.
Ion
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Aristotle
believed all matter was continuous and was based on earth, wind, fire, and water.
Avogadro
created Avogadro's Number; the number of particles in one mole (6.02214179 x 10_23)
