Patterns in properties of elements
- Atoms of each element have different proton numbers
- Arranging the elements in order of their properties gives repeating patterns in the properties of elements
- Doborenier: studied elements in groups of 3 (traids). Average RAM of three elements = RAM of the middle element. Didn't work for all elements so wasn't accepted.
- Newland: Law of octaves - every 8th element has similar properties (arranged in order of RAM). Didn't work for all so wasn't accepted.
- Mendeleev: Arranged by RAM. He left gaps in the table for undiscovered elements and he predicted their properties.His table was accepted when we began to find new elements that fit into the table and the predictions he made about them were correct. Used today.
- State symbols: S - solid, L - liquid, g - gas, aq - dissolved in water.
Reading the periodic table:
- The periodic table is organised in order of proton numbers.
- The top number is the relative atomic mass (RAM). The letter(s) is the symbol. The word is the element name. The bottom number is the proton number.
- Vertical columns are groups. They tell you how many electrons in the outer shell.
- The rows are periods. Each new period represents another full shell of the electrons.
- On the left side of the table are the metals and on the right are the non-metals.
- The metals and non-metals are split like a staircase from Boron.
Group 1 - The alkali metals
- Electrons in group 1 are alkali metals. They're shiny when freshly cut but tarnish in moist air, due to the reaction with oxygen.
- Alkali metals react with water…
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