1C- Electron Trends

It has everything

Atomic radius

distance from the nucleus to the valence shell

Electronegativity

the ability of an atom to remove an electron

1st ionization energy

the energy required to remove the first electrons (not electrons) from an atom

Metallic character

metals losing electrons to gain a stable electrons configuration

Reactivity

metals losing electrons and non-metals gaining electrons in chemical reaction

Atomic Radius (the trend)

**Down a group:** Increase - The distance from the nucleus to the valence shell increases

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**Across a period**: Decrease- Valence shell/electrons moves closer to the nucleus (Due to the increase in core charge)

Electronegativity (the trend)

**Down a group:** Decrease - The valence shell gets further away from the nucleus. Therefore, the electrostatic attraction b/w the p+ in the nucleus and valence e- decreases.

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**Across a period:** Increase - e- are more strongly attracted to the nucleus

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1st ionization energy (the trend)

**Down a group: Decrease-**It takes less energy to remove the 1st valence e-.

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Across a period: **Increase -** It takes more energy to remove the 1st e-.

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Metallic character + Reactivity of metal

Down a group: Increase - The metals lose valence electrons more readily

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Across a period : Increase - Valence electrons do not readily come off the atoms.

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Reactivity of non metals

Down a group: Decrease **The non metals won’t gain electrons as readily**

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Across a period: Increase: Electrons are more readily gained by the atom