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Chemistry Chapter 4
Terms for chapter 4
Question | Answer |
---|---|
STM | Scanning tunneling microscope allows us to see atoms |
Democritus | Coined term Atomos and believed in what would become the particle theory of matter |
Particle Theory of Matter | Particles cannot be divided infinitely without losing their properties. |
Continuous Theory of matter | States that matter could be divided without end without changing the matter's properties. |
Aristotle | Believed in what became the continuous theory of matter. |
Law of Definite Composition | Every compound is formed of elements combined in specific ratios |
Dalton's Model | Uniformly dense sphere |
Thompson's Model | plum pudding model |
plum pudding model | Contains electrons in a sea of positive goo. |
Thompson discovered electrons because these bent towards positively charged plate in a discharge tube. | cathode rays |
Rutherford discovered the nucleus because of this. | Gold foil experiment |
Rutherford sent these through the gold foil. | alpha particles |
Atomic number is | number of protons in an atom |
Alpha particles are this. | Helium nuclei - 2 protons, 2 neutrons |
Chadwick discovered these. | Neutrons |
These have a positive charge in an atom. | protons |
These have a negative charge in an atom. | electrons |
These have no charge in an atom. | neutrons |
These are the least massive particles in an atom. | electrons |
These are the most massive in an atom. | neutrons |
The analysis of light emitted or absorbed by matter. | Spectroscopy |
He developed the idea of principle energy levels. | Niels Bohr |
Niels Bohr model of the atom | planetary model |
When all electrons are at the lowest energy level in an atom. | ground state |
Released quantities of energy from an atom are called | photons |
photons | massless light particles |
De Broglie said electrons act like | waves and particles |
Describe the path of electrons and are like probability clouds | orbitals |
It is impossible to know both the energy and the position of an electron at the same time is called the | Heisenberg Uncertainty Principle |
This model has orbitals | quantum model |
Levels in which electrons orbit the nucleus of an atom | principle energy levels |
No two electrons in an atom can have the same 4 quantum numbers | Pauli Exclusion Principle |
These are determined by the energy of electrons in the ground state. | Quantum Numbers |
The S sublevel has how many orbitals | 1 |
The P sublevel has how many orbitals | 3 |
The D sublevel has how many oribitals | 5 |
The F sublevel has how many orbitals | 7 |
The s sublevel can hold how many electrons total | 2 |
The P sublevel can hold how many electrons total | 6 |
The D sublevel can hold how many electrons total | 10 |
The F sublevel can hold how many electrons total | 14 |
As the energy of an electron increases the distance from the nucleus | increases |
The greater the sublevel the greater the ____ of the electron | energy |
Arrangement of electrons in atoms is determined by adding electrons to an atom with a lower atomic number. Lower energy levels are filled first. | Aufbau Principle |
As electrons fill a sublevel,all orbitals receive one electron with the same spin before they begin to pair up | Hund's Rule |
Protons + Neutrons | Mass number |
Atoms with the same number of protons but different numbers of neutrons | isotopes |
1 atomic mass unit (amu) = 1/12th the mass of | carbon |
The outer most electrons in the atom | valence electrons |
Atoms that have gained or lost electrons | ions |
Positive ions | Cations |
negative ions | anions |
Cations have ___ protons than electrons | more |
Anions have ____ protons than electrons | fewer |