Atomic Structure & Periodic table.
The periodic table of elements, is a way to arrange chemical elements. It's arranged by Metals and Non-metals, also by in order of increasing atomic numbers (number of protons) and chemical properties. The table consists of 18 rows and 7 columns. The vertical columns are called groups which indicates the number of valance electrons in the outer shell. The horizontal rows are called periods which shows the amount of electron shells in the atom.
There are 8 groups in the periodic table. They have more significant trends than periods.
Group 1 are also known as alkali metals, they are the most reactive metals in the periodic table. They react spontaneously with water and oxygen, they do not occur frequently in nature, they are stored in oil since they are highly reactive. Alkali metals consists : Lithium, Sodium, Potassium, Cesium, Rubidium and Francium. Their reactivity changes as it goes down the group, it gets more reactive and dense as you go down the group; which means the element is more readily to lose its electron to form a positive ion, due to the increase in the size of atomic radius.And the melting and boiling points gets higher as you go up the group. Alkali metals create alkaline solution and hydrogen. Eg; Sodium + Water ---> Sodium hydroxide + Water. Physical properties: They are shiny, could be cut by a knife, Good conductor of heat and electricity, Ductile and Malleable, Low density, Low melting and boiling points. Chemical Properties: Have 1 valance electrons, react vigorously with water to produce alkalis and hydrogen gas.
Group 7 is known as halogens, they consists Fluorine, Chlorine, Bromine, Iodine and Astatine. They exist as diatomic molecules as they can achieve stable electronic structure. Unlike group 1 elements the reactivity goes higher as you go up the group, and it gets more solid as you go down the group, and the colour tends to get darker down the group. Physical properties: Poor conductor of electricity and heat, Brittle in solid state, colored molecules, Low boiling and melting points. Chemical Properties: Have 7 valance electrons
Group 8 or Group 0 are known as Noble gases. They are highly unreactive because they have maximum number of electrons in the valance shell. Uses of noble gases :Helium in Balloons, Neon & Argon in Lightbulbs.
Transition metals are metallic elements that serve as a bridge, or a transition between the two sides of the table!:D