Read formulae
H₂O
Water
2H₂ + O₂ → 2H₂O
"Hydrogen gas plus oxygen gas yields water."
A strong, malleable metal used in construction, steelmaking, and machinery.
Fe (Iron)
The lightest and least dense alkali metal, it is soft enough to be cut with a knife.
Lithium (Li)
The Only Liquid Metal at Room Temperature
Mercury (Hg)
CO₂
Carbon Dioxide
N₂ + 3H₂ → 2NH₃
Nitrogen gas plus hydrogen gas yields ammonia.
A lightweight, corrosion-resistant metal used in aircraft, cans, and electronics.
Al (Aluminum)
The most reactive stable metal, liquid at slightly above room temperature. Explodes upon contact with water.
Cesium (Cs)
The Coldest Substance
Liquid Helium (He) reaches -269°C (-452°F), just 4°C above absolute zero.
Fe₂O₃
Iron(III) Oxide
4Fe + 3O₂ → 2Fe₂O₃
Iron plus oxygen yields iron(III) oxide (rust).
A precious, non-reactive metal valued for jewelry, electronics, and currency.
Gold (Au)
A soft, silvery metal that reacts violently with water, producing flames.
Potassium (K)
The Radioactive Element in Smoke Detectors
Americium-241 (Am) is used in ionization smoke detectors—it emits alpha particles to detect smoke.
NO₂
Nitrogen Dioxide
CH₄ + 2O₂ → CO₂ + 2H₂O
Methane plus oxygen yields carbon dioxide and water
Makes up ~78% of air; vital for proteins, DNA, and fertilizers (e.g., ammonia).
Nitrogen (N)
A rare, radioactive alkali metal with no stable isotopes.
Francium (Fr)
The Most Expensive Element
Francium (Fr) is worth $1 billion per gram (if you could isolate it). It’s so rare that only 20-30 grams exist naturally in Earth’s crust at any time!
PbO
Lead(II) Oxide
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy
Glucose plus oxygen yields carbon dioxide, water, and energy
Glows in the dark; found in DNA and fertilizer.
Phosphorus (P)
A soft, silvery-white metal that ignites spontaneously in air. Used in atomic clocks due to its precise frequency vibrations.
Rubidium (Rb)
The Deadliest Element?
Polonium-210 is so radioactive that a single gram can reach 500°C (932°F) from its own decay heat.