Final Exam Terms Flashcards
Dalton’s Atomic Theory
All matter is composed of extremely small particles called atoms. Atoms cannot be subdivided, created, or destroyed.
Law of Definite Proportions
chemical compound will always have the same proportions or amount of each element by weight, no matter what the amount is, or source.
Law of Multiple Proportions
when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.
Rutherford Experiment
A beam of alpha particles was aimed at a piece of gold foil. Most alpha particles passed through the foil, but a few were scattered backward. This showed that most of the atom is empty space surrounding a tiny nucleus.
Hess’s Law
Hess’s law states that the energy change in an overall chemical reaction is equal to the sum of the energy changes in the individual reactions comprising it.
1st Law of Thermodynamics
energy cannot be created or destroyed
2nd Law of Thermodynamics
The Second Law of Thermodynamics states that the state of entropy of the entire universe, as an isolated system, will always increase over time.
Bohr Model
In an atom, electrons (negatively charged) revolve around the positively charged nucleus in a definite circular path called orbits or shells.
Grahams Law
Graham’s law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight.
Valence Bond Theory
Valence bond (VB) theory assumes that all bonds are localized bonds formed between two atoms by the donation of an electron from each atom.
Molecular Orbital Theory
electrons in a molecule are not assigned to individual chemical bonds between atoms, but are treated as moving under the influence of the atomic nuclei in the whole molecule.
