Gases:
* Oxygen (O): Essential for respiration and combustion.
* Nitrogen (N): The most abundant gas in the atmosphere.
* Hydrogen (H): The lightest element, used as a fuel.
* Helium (He): A noble gas, used in balloons and MRI machines.
* Neon (Ne): A noble gas, used in signs and lasers.
* Argon (Ar): A noble gas, used in welding and light bulbs.
* Chlorine (Cl): A reactive halogen, used in water treatment and disinfectants.
* Fluorine (F): The most reactive element, used in toothpaste and refrigerants.
* Bromine (Br): A reddish-brown liquid at room temperature, used in pesticides and flame retardants.
Solids:
* Carbon (C): Forms the basis of organic chemistry, found in diamonds, graphite, and coal.
* Phosphorus (P): Used in fertilizers and matches.
* Sulfur (S): Found in gunpowder and sulfuric acid.
* Selenium (Se): Used in photocopiers and solar cells.
* Iodine (I): Used in disinfectants and medications.
* Boron (B): Used in glass and detergents.
* Silicon (Si): Used in semiconductors and computer chips.
* Germanium (Ge): Used in transistors and fiber optics.
* Arsenic (As): Toxic but used in some pesticides and semiconductors.
* Antimony (Sb): Used in alloys and fire retardants.
* Tellurium (Te): Used in solar cells and semiconductors.
* Polonium (Po): Radioactive, used in some applications but is highly dangerous.
Liquid:
* Bromine (Br): As mentioned above, bromine is a reddish-brown liquid at room temperature.
Remember that the dividing line between metals and non-metals is not always clear-cut. Some elements, like silicon and germanium, are classified as metalloids, possessing properties of both metals and non-metals.
