AT_Atomic Theory Module Overview

Atomic Theory Module Overview

Introduction

In this module you will learn how matter is classified, the history of atomic theory, subatomic particles, modern atomic theory, electron configuration, the periodic table and its trends, and spectroscopy.

Module Lessons Preview

• How is matter classified?
• What were the scientific laws upon which Dalton's atomic theory was formed?
• What were the failures of Dalton's atomic theory?
• What are the parts of an atom and their functions?
• What were the successes and failures of the Bohr model of the atom?
• What is the modern atomic theory and how did it develop?
• How do electrons fill in orbitals and what is the significance of their distribution?
• How is the periodic table arranged?
• What differentiates metals from nonmetals?
• What are the basic trends shown on the periodic table?
• What is Coulomb's Law and how is it related to electrons?
• How is spectroscopy used in experimentation?

Key Terms

1. Anion - a negatively charged ion
2. Atomic Mass - the relative mass of the atoms that make up an element, based on the scale where the mass of an atom of carbon-12 is exactly 12 u
3. Atomic Mass Units - a unit developed by chemists, given the symbol u, to measure the mass of atoms
4. Atomic Number - the number of protons in the nucleus of an atom
5. Atomic Radius - a term used to describe the size of the atom
6. Atomic Spectrum - the line spectrum produced when energized or excited atoms emit electromagnetic radiation
7. Atomic Theory - the idea that matter is made up of fundamental particles called atoms
8. Aufbau Principle - a set of rules enabling the construction of an electron structure of an atom from its atomic number
9. Cation - a positively charged ion
10. Chemical Properties - how substances change into other substances in chemical reactions
11. Compound - combination of elements in fixed proportions
12. Core Electrons - the inner electrons of an atom that are not exposed to the electrons of other atoms when chemical bonds form
13. Coulomb's Law - a law stating the force between two charges is proportional to the amount of charge on both charges and inversely proportional to the square of the distance between them; $F = \frac{Q_{1}Q_{2}}{{r_2}}$
14. Diamagnetic - not capable of being attracted to a magnet
15. Effective Nuclear Charge - the. net charge of an electron experience in an atom with multiple electrons
16. Electromagnetic Energy - energy transmitted by wavelike oscillations in the strengths of electrical and magnetic fields
17. Electromagnetic Radiation - the success series of wavelike oscillations in the strengths of electrical and magnetic fields associated with light, microwaves, gamma rays, ultraviolet rays, infrared rays, etc.
18. Electromagnetic Spectrum - the distribution of frequencies of electromagnetic radiation among various types of such radiation-microwave, infrared, visible, ultraviolet, X, and gamma rays
19. Electron - a subatomic particle found outside the nucleus that has a charge of -1 and a mass of 0.0005486 u
20. Electron Configuration - the distribution of electrons in an atom's orbitals
21. Element  - substance that cannot be decomposed into something simpler by a chemical reaction
22. Energy Level - the possible locations around an atom where electrons having specific energy values
23. Energy Levels - a particular energy an electron can have in an atom or molecule
24. Extensive Property - dependent on sample size
25. Frequency - the number of cycles per second of electromagnetic radiation
26. Ground State - the lowest energy state of an atom or molecule
27. Group - column down a periodic table, also known as a family
28. Heinsenberg's Uncertainty Principle - the scientific principle stating that it is impossible to determine with perfect accuracy both the position and momentum of a particle at any given point in time
29. Hertz - the SI unit of frequency; 1 cycle per second
30. Heterogenous - consisting of two or more phases
31. Homogenous - consisting of only a single phase
32. Hund's Rule - electrons that occupy orbitals of equal energy are distributed with unpaired spins as much as possible among all such orbitals
33. Intensive Property - independent of sample size
34. Ion - an electrically charged particle
35. Ionic Radius - a term used to describe the size of an ion
36. Ionization Energy - energy needed to remove an electron from an isolated gaseous atom, molecule, or ion in its ground state
37. Isotope - an atom of an element that has a different number of neutrons in the nucleus
38. Law of Conservation of Mass  - No detectible gain or loss of mass occurs in chemical reactions
39. Law of Definite Proportions - in a given chemical compound, the elements are always combined in the same proportion by mass
40. Mass Number - the number of protons and neutrons in the nucleus of an atom
41. Matter - anything that has mass and takes up space
42. Metalloids - have properties of both metals and nonmetal and are semiconductors of electricity
43. Metals - found in the lower left hand side of the periodic table. Exhibit metallic luster, are ductile, malleable, and conduct electricity
44. Mixture - two or more substances combined so that each maintains its own chemical identity
45. Neutron - a subatomic particle found in the nucleus that has a charge of 0 and a mass of 1.0086649 u
46. Noble Gas Configuration - an abbreviation in an atom's electron configuration where the previous noble gas's electron configuration is replaced with the noble gas's element symbol in brackets
47. Nonmetals - found in the upper right hand side of the periodic table. Are brittle, lackluster, are non-conductors of electricity, and are often gases
48. Nucleus - the hard, dense core found in the center of an atom that contains the protons and neutrons
49. Orbital Diagram - a diagram showing an atom's orbitals in which the electrons are represented by arrows to indicate paired and unpaired electrons
50. Orbital - a region of space when an electron is likely to be found
51. Outer electrons - the electrons in the occupied shell with the largest principal quantum number
52. Paramagnetism - the weak magnetism of a substance whose atoms, molecules, or ions have unpaired electrons
53. Period - row across a periodic table
54. Photon - a unit of energy in electromagnetic radiation equal to hv, where v is the frequency of radiation, and h is Planck's Constant
55. Physical Properties - measured without changing the chemical makeup of the sample
56. Planck's Constant - the ratio of the energy of a photon to its frequency; 6.6260755 x 10-34 J Hz-1
57. Proton - a subatomic particle found in the nucleus that has charge of +1 and a mass of 1.0072765 u
58. Pure Substance - elements and compounds
59. Quantized - descriptive of discrete, definite amount
60. Quantum Mechanics - mathematical method of treating particles on the basis of quantum theory, which assumes that energy (of small particles) is not infinitely divisible
61. Quantum Theory - the physics of objects that exhibit wave/particle duality
62. Relative Abundance - the ratio of the number of atoms of a particular isotope in a sample of an element to the number of atoms of a specified isotope, or to the total number of atoms in the element
63. Representative Elements - A-group elements (Groups 1, 2, and 13-18), also known as main group elements
64. Rydberg Equation - an equation used to calculate the wavelengths of all the spectral lines of hydrogen
65. Solution - a one phase mixture
66. Sublevel - a group of like orbitals (s, p, d, f)
67. Transition Elements - B-group elements (Groups 3-12)
68. Valence Electrons - the electrons of an atom is its valence shell
69. Visible Spectrum  - the region of the electromagnetic spectrum whose frequencies can be detected with the human eye
70. Wavelength - the distance between crests of electromagnetic radiations

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Atomic Theory Practice Problems

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