C2: The Periodic Table

Those are periods.

Groups.

It equals the amount of electrons in the outer shell

John Newlands

He ordered it by atomic mass, but it was incorrect as elements were placed in innappropriate groups

Dmriti Mendeleev. He added gaps for undiscovered elements along with saying there might be undiscovered elements.

He predicted the properties and masses of the undiscovered elements. He ordered elements via relative mass due to discovery of protons and isotopes

• High melting points • High boiling points • Good conductors of heat and electricity

• Low melting points • Low boiling points • Good insulators of heat and electricity

They are found in Group 1 on the left side of the table and are metals. They are very reactive. Their outer shell has 1 electron in it, which is usually given away as chemical reactions. As we go down the group, the reactivity increases. They must not react with water. They have high melting and boiling points and high densities.

It has a 2,1 structure. Its the least reactive It floats on the surface of water and releases hydrogen gas bubbles. It burns with a crimson flame, when contacted with oxygen

Has an extra shell added, 2,8,1. Its more reactive than lithium and a much more greater distance from the positive charge of the nucleus. Its outer electron is strongly attracted to the positively charged nucleus. It floats on the surface of water releasing enough heat to melt sodium. It moves quicker on water surface, and emits a yellowish orange flame when contacting with oxygen

It has an extra shell added, 2,8,8,1. Its more reactive than sodium and lithium and its outer electron is least strongly attracted to the nucleus. It floats on water, but is more vigorous. It also burns with a lilac flame when combined with oxygen.

It creates hydroxide.

Noble Gases are found in Group 0, and have similar properties eg: colourless. They are the most unreactive and are found on the right side of the Periodic Table. They already have a full outer shell, except helium. Every other element but helium does not need to gain or lose electrons. They also exist as single atoms, meaning they are monotomic. They have low melting and boiling points, low densities, inert, exist as single atoms and are colourless.

Halogens are in Group 7 and have 7 electrons in their outershell. They are very reactive and are also diatomic, meaning they share electrons to make diatomic molecules. As we go down the group, the reactivity decreases. They are all colourless.

Salts

They are found in the middle of the table, and are much stronger and harder than alkali metals. They also have high melting points and are useful for cooking. They have high densities and more mass for volume than alkalis. They are also less reactive than alkalis and can form ions with different positive charges. They also form different colour compounds

Monotomic

When a less reactive halogen is displaced by a more reactive halogen from a compound

Diatomic

Simple distillation Fractional distillation Paper chromatography Crystallisation Filtration

Separating a solvent (liquid) from a solution

Because the dissolved solute has a much higher boiling point than the solvent. When we heat a solution, solvent vapour leaves the solution. It moves away and is then cooled and condensed. The remaining solution becomes more condensed and the amount of solvent is then decreased