📝 Materials: Metals and Non-Metals
Pure substance
➤ Materials made up of same kind of particles are known as pure substances. Elements and compounds are pure substances.
Element
➤ An element is made up of atoms of the same kind.
Elements differ from each other in their physical and chemical properties, as different elements consist of atoms of different kind.
Classification of Elements
There are 118 elements known at present. It is difficult to study and describe all the properties of these elements separately. Hence, the element showing similar properties are grouped together.
👉 Metals can be
distinguished from non-metals on the
basis of their physical and chemical
properties.
Appearance and Hardness of Materials
Chemical Properties of Metals and Non-metals
👉 Metals react with Oxygen
Metal + Oxygen `\rightarrow` Metal Oxide
Examples
`Mg + O_2 \rightarrow MgO`
`Na + O_2 \rightarrow Na_2O`
The phenomenon
of rusting of iron
Iron `(Fe)` + Oxygen `(O_2)` + Water `(x H_2O) \rightarrow` Hydrated iron oxide (rust) `(Fe_2O_3.xH_2O)`
Nature of rust 👉 Basic
Activity
Collect a spoonful of rust and
dissolve it in a very little amount of
water. You will find that the rust
remains suspended in water. Shake
the suspension well. Test the
solution with red and blue litmus
papers.
👉 Red litmus turns blue
👉 In general, metallic
oxides are basic in nature.
Facts
Comments
Post a Comment