Atoms and Molecules
- History of the Atom
- Models for the Atom
- Subatomic Particles
- Periodic Table
- Periodic Trends
- Polyatomic Ions
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|Atoms and Molecules - Periodic Trends|
Ionization energy decreases down a group in the periodic table due to the fact that the outermost electrons are further away from the nucleus. The increase in distance between the positive nucleus and the negative electrons creates a weaker attraction between the two. As a result, less energy is needed to remove an electron from elements located lower on the periodic table. Ionization energy increases as you move across a row of the periodic table. This is due to a smaller atomic radius and a greater attraction between the nucleus and the electrons. This increase in attraction makes it so that a greater amount of energy is needed to remove an electron and ionize that atom.
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The quantity of energy required to remove an electron from a neutral atom or molecule or from a positive ion.
The ionization energy is the minimum energy required to remove an electron from the ground state of the ioslated gaseous atom. Ionization energy is measured in electron volts (eV) or kilojoules per mole of atoms (kJ mol-1).
Atom(g) + Ionization Energy → Ion+(g) + electron-
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A visual representation of the periodic trends in ionization energy.
This video explains the first, second....nth ionization energies.
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