8 Summary
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Review Module 2 Material
Modern Atomic Theory Review
Cation (+): |
Isotopes: |
Anion (-): |
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One or more atoms that has lost an electron(s). A main group METAL will LOSE electrons to form a CATION with the same number of electrons as the nearest noble gas. |
Are atoms of the same type that have a different number of neutrons. Isotopes of elements are distinguished by the mass number (A). |
Elements that have unpredictable properties. A main group NONMETAL will GAIN electrons to form an ANION with the same number of electrons as the nearest noble gas. |
Atomic Mass: |
We know: |
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Is the weighted average of isotopic masses based on the natural abundance of each isotope. The natural abundance is the relative amount of each isotope found in a natural sample of any element. Natural abundance is relatively constant and unique for each element. |
Isotopes are atoms of the same type that have a different number of neutrons. The mass of an atom is dictated by the mass of protons and neutrons because the mass of an electron is negligible in comparison. |
Atomic Mass Calculations:
Atomic mass for an element can be calculated with the following formula:
In simple terms this formula is telling us that atomic mass can be calculated by:
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1) Multiplying each isotopic mass of an element by its relative abundance. |
2) Adding the resulting masses of the isotopes together. |
Defining the Mole:
The mole is defined using the C-12 isotope.
One mole = number of atoms in exactly 12 g C-12.
12 g of C-12 = 1 mole of C-12 atoms = exactly C-12 atoms
The mass of one mole of C-12 atoms is 12 g
1 mole of carbon (C) = atoms
Periodic Trends
Metals: |
Non-Metals: |
Metalloids: |
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Generally good conductors of heat and electricity Tend to lose electrons in a chemical reaction |
Generally poor conductors of heat and electricity Tend to gain electrons in a chemical reaction |
Have properties of both metals and non-metals. |
Main Group: |
Transition Metals: |
Lanthanoids and Actinoids: |
| Elements that have predictable properties | Elements that have unpredictable properties. | Elements that are placed separately for a more compact periodic table. They have similar properties to the elements lanthanum and actinium. |
Groups
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Each column in the periodic table is called a group and numbered 1-18 |
Each row in the periodic table is called a row and numbered 1-7 |
The elements in a group have similar properties. |
For example: The noble gases in group 18 are all relatively unreactive. |
Atomic Structure
Orbital: |
Spin Quantum Number |
| The likely position of an electron in an atom described by a probability distribution map. |
Spin is intrinsic to all electrons, it is quantized, with only two orientations; spin up or spin down. Value = OR |
Principal Quantum Number (n) |
Angular Momentum Quantum Number (l) |
Magnetic Quantum Number |
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Orbital’s size and energy level of an electron. A whole number 1,2,3,4….. n increases with an electron’s energy and distanc