Group One elements in the Periodic Table are called the alkali metals. They are lithium, sodium, potassium, caesium and rubidium. They all react vigorously with air and water, so they have to be stored in oil.
Sodium is more reactive than lithium and potassium is more reactive than sodium. You can tell, because potassium reacts extremely vigorously and quickly with water, whereas lithium less quickly and vigorously, with sodium somewhere in the middle of the reactivity series. As for caesium and rubidium - their reaction is.... explosive!
Alkali metals have a lower density than water, so they float when they react with it. The products of this reaction are the metal hydroxide (for example, sodium hydroxide when sodium reacts) and hydrogen.
Here is the general chemical equation. All you would have to do is substitute the word 'metal'; with the name of the metal you are writing the reaction about:
metal + water metal hydroxide + hydrogen
Group One metals also react with Group Seven non-metals (for example: chlorine, bromine, iodine) and they make a compound which combines both of them. An example is:
potassium + iodine potassium iodide
Note how the endings change: -ine becomes -ide.
Group Seven elements are called halogens and the compounds they make with Group One elements are called metal halides.
Metals form compounds with the carbonate group (-CO3), the metal carbonates. Metal carbonates decompose (break down) with heat and form a metal oxide and carbon dioxide:
Rusting is a form of chemical reaction of metals with oxygen and water. The chemical equation for rusting of iron is:
iron + oxygen + water hydrated iron(III) oxide
Iron(III) is one of the two types of iron; the other one is Iron(II). Rusting is an example of oxidation. The name comes from the reaction with oxygen to form an oxide.
Metal compounds react with acids. Specifically:
metal oxide + acid salt + water
Example: copper oxide + hydrochloric acid copper chloride + water
metal hydroxide + acid salt + water
Example: sodium hydroxide + nitric acid sodium nitrate + water
metal carbonate + acid salt + water + carbon dioxide
Example: calcium carbonate + sulfuric acid calcium sulfate + water + carbon dioxide
A metal oxide is a compound of a metal with oxygen. A metal hydroxide is a compound of a metal with the hydroxide group (-OH). A salt is a compound made of a metal and a non-metal. Hydrochloric acid gives chlorides, nitric acid gives nitrates and sulfuric acid gives sulfates.