Differentiate between metal and non-metal on the basis of their chemical properties.
Metal | Non-metal |
Metals are electropositive. | Non-metals are electronegative. |
They react with oxygen to form basic oxides. $4 Na + O _{2} \longrightarrow 2 Na _{2} O$ These have ionic bonds. |
They react with oxygen to form acidic or neutral oxides. $C + O _{2} \longrightarrow CO _{2}$ These have covalent bonds. |
They react with water to form oxides and hydroxides. Some metals react with cold water, some with hot water, and some with steam. $2 Na +2 H _{2} O \longrightarrow 2 NaOH + H _{2} \uparrow$ |
They do not react with water. |
They react with dilute acids to form a salt and evolve hydrogen gas. However, $Cu ,\, Ag ,\, Au , \,Pt ,\,Hg$ do not react. $2 Na +2 HCl \longrightarrow 2 NaCl + H _{2} \uparrow$ |
They do not react with dilute acids. These are not capable of replacing hydrogen. |
They react with the salt solution of metals. Depending on their reactivity, displacement reaction can occur. $CuSO _{4}+ Zn \longrightarrow ZnSO _{4}+ Cu$ |
These react with the salt solution of non-metals. |
They act as reducing agents (as they can easily lose electrons). $Na \longrightarrow Na ^{+}+ e ^{-}$ |
These act as oxidising agents (as they can gain electrons). $Cl _{2}+2 e ^{-} \longrightarrow 2 Cl ^{-}$ |
Give reasons : Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
You are given a hammer, a battery, a bulb, wires and a switch.
$(a)$ How could you use them to distinguish between samples of metals and non-metals ?
$(b)$ Assess the usefulness of these tests in distinguishing between metals and non-metals.
$(i)$ Write the electron-dot structures for sodium. oxygen and magnesium.
$(ii)$ Show the formation of $Na _{2} O$ and $MgO$ by the transfer of electrons.
$(iii)$ What are the ions present in these compounds ?
Why is sodium kept immersed in kerosene oil ?
Name two metals which are found in nature in the free state.