Periodic Table
- Created by: Uswa
- Created on: 24-03-13 14:23
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- Periodic Table
- Facts
- Newlands and then Meldeev attempted to classify elements by arranging them in order of their ATOMIC WEIGHTS
- This list can be arranged in a table, so elements with similar properties are in columns [GROUPS!]
- It is called a periodic table as similar properties occur at regular intervals
- Early Periodic Table
- Incomplete
- Some elements placed in inappropriate groups if strict order of atomic weights was followed
- E.g. non-metals and metals were mixed up
- Mendeleev solved these problems by leaving GAPS for elements that he thought had NOT BEEN DISCOVERED YET
- Modern Periodic Table
- Electrons, Neutrons and Protons were discovered in early 20th Century
- Arranged in order of their atomic [proton] numbers
- In terms of their electronic structures
- So all elements are placed in APPROPRIATE groups
- Elements in the same group have the same no. of electrons in their highest occupied energy level
- [Outer shell]
- Facts
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