Mr.
...according to atomic weights and properties. Made predictions which were later proven accurate.
Henry Moseley - utilised X-Ray. Said that periodic table should be based on atomic numbers of elements.
Dalton = atom as the basic unit of an element that can enter into a chemical combination// very small and indivisible// everything is made up of discreet building blocks, that is atoms.
J.J Thompson - electrons - cathode ray - studying the deflection of a ray of high-speed electrons fired at a fluorescent screen and deflected with the aid of magnetic fields and electric fields.
The charge of an electron is -1.60 * 10^-19 C // The mass of an electron is 9.09 * 10^-28 g.
Fe2+ is ferrous ion // Fe3+ is ferric ion // Silicide = Si4- // Nitride N3- // Phosphide P3- // Sulfide S2- // Carbonate (CO3)2- // Chromate (CrO4)2- // Dichromate (Cr2O7)2- // Permanganate (MnO4)- // Peroxide (O2)2- // Sulfide S2- // Sulfite (SO3)2- //
An example of electron configuration : 1s2,2s2,2p6,3s2,3p6,3d10,4s2,4p6,4d10,4f14....
The type of orbital of the first element in a period corresponds to the period number. For example, Lithium is the first element in period 2. It's valence electron is in the 2s^1 orbital.
The first ionisation energies increase from left to right across a period.
Atomic radii decrease from left to right across a period due to the increase of nuclear charge when additional protons pull additional electrons closer to the centre. // Inert gas elements have a slight increase in atomic radii because of the electron repulsion of the filled valence shell.
Ionic radius differs from atomic radius. // For metals, the electron(s) lost causes the radius to decrease because of the lost of negative charge// Non-metals tend to gain electrons. Therefore, the increase in negative charge causes the ionic radius to be higher than the atomic radius.
The ELECTRO-NEGATIVITY of an...
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