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Chemistry Summative Notes - Coggle Diagram
Chemistry Summative Notes
Periodic Table
The Periodic Table is a Table that has all the 118 Elements known to Mankind
All Elements are arranged in the order of their chemical properties
The Horizontal Rows are called "Periods" and the Vertical Columns are called "Groups"
Octet Theory
Made by Niels Bohr
Theory States that an Atom must have 8 Electrons in its Valence shell in order for it to achieve stability
The Group an Atom is in determines the number of electrons it has in its valence shell. Ex: Since Oxygen is in Group 6, it has 6 electrons in its valence shell, which means Oxygen requires 2 more Electrons to attain stability
The Period an Atom is in determines the number of electron shells it has. Ex: Xenon is in Period 5, so it has 5 electron shells
History of The Periodic Table
Dobereiner's Triads:
He stated that the Atomic Mass of the Element in the middle is equal to the average of the other 2 Atomic Masses
Newland's Octaves:
He stated that Element has chemical properties that are similar to the 8th Element preceding it
Mendeleev's Periodic Table:
Dmitri Ivanovich Mendeleev is credited to be "The Father of The Periodic Table". He arranged Elements in the ascending order of their atomic mass. Mendeleev's Law was "The Physical and Chemical Properties of an Element are a periodic function of their atomic mass"
The Modern Periodic Table:
Created by Henry Mosely in 1913, the major difference from Mendeleev's Periodic Table is that the elements in this table are arranged in the ascending order of their atomic number. The law is "The physical and chemical and chemical properties of an Element are a periodic function of their atomic number."
Groups in the Periodic Table
Group 1: Alkali Metals
Group 2: Alkaline Earth Metals
Group 7: Halogens
Group 8/Group 0: Noble Gases/Inert Gases
Atomic Radii:
The Distance from the Atomic Nucleus to the outermost stable Valence Electron. Atomic Radii decreases as you go through a Period due to Effective Nuclear Charge, and increases as you go down a group as more and more electron shells are being added
Ionic Radii:
Half the Distance between 2 Ions that are barely touching each other
Types of Ions
Cations (+ve Charge)
Anions (-ve Charge)
Ionisation Energy:
The Energy required for an Atom to remove an Electron. In this process, the Atom loses energy and becomes a Cation
Electron Affinity:
How easy it is for an Atom to accept Electrons. usually, in this process, the Atom gains energy and becomes an Anion
Electronegativity:
The tendency for an Atom to attract electrons in order to achieve stability by means of bonding
The Atomic Radii decrease as you go through a period, but the Ionization Energy, Electron Affinity, and Electronegativity increase, which means that they are inversely proportional to the Atomic Radii of an Element