10.Metals & Non-metals: Electron Arrangement & Properties

Metals & Non-metals: Electron Arrangement & Properties

Based on the video, here are the structured notes on the differences between metals and non-metals regarding their atomic structure and physical characteristics.

1. Ion Formation & Reactivity

  • Metals: Found toward the bottom left of the periodic table. They have few electrons in their outer shell, making it easy to lose them and form positive ions (e.g., Ca2+).

  • Non-metals: Found on the right side. They either do not form ions (like Carbon) or they gain electrons to form negative ions (e.g., Cl-).

  • Reactivity Trend: Metals become more reactive toward the bottom of the table. This is because elements further down have more shells, placing the outer electrons farther from the positive nucleus. This weaker attraction allows the atom to lose electrons more easily during a reaction.

2. Physical Properties of Metals

Metals are held together by metallic bonding, which is very strong and responsible for their unique traits:

  • Malleable: They can be bent or hammered into shape without snapping.

  • Conductors: They are excellent conductors of both heat and electricity.

  • High Melting/Boiling Points: Most stay solid even at very high temperatures; some won't melt even at 2,000°C.

  • Other Traits: They are usually shiny (lustrous) and sonorous (make a ringing sound when hit).

3. Physical Properties of Non-metals

Non-metals generally exhibit properties opposite to metals:

  • Appearance & Texture: They tend to be dull in color and brittle (they shatter or break easily rather than bending).

  • Melting/Boiling Points: Generally low; many are gases at room temperature.

  • Insulators: They are poor conductors of heat and electricity.

  • Density: They generally have lower densities than metals, meaning they weigh less for a given volume.

4. Transition Metals

Located in the center of the periodic table, these are "typical" metals with extra unique properties:

  • Multiple Ions: They can form more than one type of ion (e.g., Chromium can form 2+, 3+, or 6+ ions).

  • Colored Compounds: Their ions often create brightly colored solutions (like blue, green, or orange).

  • Catalysts: They are very effective at speeding up chemical reactions without being used up themselves.

    • Examples: Iron is used to make ammonia; Nickel is used in making margarine.