Reactivity of metals
Reactivity of some metals in decreasing order:
Potassium
Sodium
Calcium
Magnesium
Aluminum
Zinc
Iron
Lead
Copper
Mercury
Silver
Platinum

 Mnemonic:
Please Send Cats, Monkeys And Zebras In Large Cages Make Sure Padlocked

More mnemonics in this category

Aldohexoses
The 8 aldohexoses in Organic Chemistry: Allose, Altrose, Glucose, Mannose, Gulose, Idose, Galactose, Talose "All Altruists Gladly Make Gum In Gallon Tanks"
Diatomic elements
Diatomic elements: H, N, F, O, I, Cl, Br (Beer(liquid), Ice (solid)) Have No Fear Of Ice Cold Beer Brinclhof
First Elements of the Periodic Table
The first 20 Elements of the Periodic Table: Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminium, Silicon, Phosphorus, Sulphur, Chlorine, Argon, Potassium, Calcium. The symbol for sodium is "Na". Some mnemonics refer to the symbol "Na" instead of sodium. Harry He Likes Beer Bottle Cold, Not Over Frothy. Nelly's Nanny Might, Although Silly Person, She Climbs Around Kinky Caves;
Fractional distillation of crude oil
To remember the products of fractional distillation of crude oil: refinery gases, gasoline, naphtha, kerosine, diesel oil, fuel oil, lubricating fraction (e.g. greases, wax) and bitumen Really Great (and Noble) Kings Don't Forget (Ladies') Birthdays
Group 17 in periodic table
The elements of group 17 in the periodic table: Fluorine, Chlorine, Bromine, Iodine, Astatine, Tennessine Free Cookies Bring Infinite Amusement Tonight
Oxidation and Reduction
Oxidation is losing electrons, Reduction is gaining electrons. "OILRiG" - Oxidation is losing electrons, Reduction is gaining electrons. 'I' in Oil stands for increase in Electronegativity Value. "LEO said GER" -Losing Electrons is Oxidation, Gaining Electrons is Reduction
Series of alkanes
The series of alkanes: Methane, Ethane, Propane, Butane, Pentane, Hexane My Enormous Penguin Bounces Pretty High