Elements, Compounds and Mixtures

Elements is the simplest kind of matter and there are over 100 of them. Elements are grouped in a periodic table which consists of periods and groups. Elements in the same period are lined up according to their atomic number on the bottom left-hand corner, while the atomic mass is on the top. Periods are horizontal. Elements in the same group share similar chemical properties, and are vertical. Each element has an special symbol. Fron the left to the right of each period, the elements on the left are metal, and non-metal are on the right. Metals and non-matals have different properties, for example, iron and carbon. Iron is ductile and has high density while carbon is brittle and has low density.
Elements also have different uses. Aluminium is used to make foils and drink cans while, Chlorine is used to make bleach.
A compound consists of 2 or more elements chemically combined together. A mixture consists of 2 or more substances which are not joined together chemically, and it can be made up of elements , compunds or both. Elements in a compound are have different ratios, like 2:1, and compounds have a chemical formula. metallic elements always have their names come first in the compound's name. Mixtures have no chemical formula no given ratio. Compounds can be separated chemically by releasing energy. Mixtures can be separated by physical force.
Something interesting I did in the lab was to burn a magnesium with a bunsen burner. Miss leong asked gave everyone a small magnesium plate. We then use a pair of tongs to burn it in the flame. After burning the magnesium, it lit up into bright white light. The originally grey magnesium turned white after cooling it. This proves that elements are chemically combined and the release ofenergy as light was produced and the magnesium combined with oxygen to become magnesium oxide.


Here is a video I have found, enjoy :D