The order of reactivity of metals, from most to least reactive, is:

• Potassium: Most reactive and easily forms positive ions
• Sodium: Second most reactive
• Lithium: Third most reactive
• Calcium: Fourth most reactive
• Magnesium: Fifth most reactive
• Aluminum: Sixth most reactive
• Zinc: Seventh most reactive
• Iron: Eighth most reactive
• Tin: Ninth most reactive
• Lead: Tenth most reactive
• Hydrogen: Eleventh most reactive
• Copper: Twelfth most reactive
• Silver: Thirteenth most reactive
• Gold: fourteenth most reactive
• Platinum: Fifteenth most reactive