Chemical Properties of Metals and Non-Metals: Position, Reactions
Chemical Properties of Metals and Non-metals: Metals and non-metals are the elements that surround us. As a result, it’s crucial to determine if a given element is a metal or a non-metal. The two sorts of materials are metals and non-metals. Non-metals, such as sulphur and phosphorus, are insulators, whereas metals, such as aluminium and copper, have excellent electrical and thermal conductivity.
The metals are present on the left-hand side, in the middle and at the bottom of the periodic table. On the other hand, non-metals are placed on the extreme right-hand side. In this article, we will discuss about chemical properties of metals and non-metals in detail. Scroll down to learn more!
Metals and Non-metals
At present, one hundred fourteen \((114)\) elements are known to us. These include metals, non-metals and metalloids. The properties and characteristics of metalloids are intermediate to metals and non-metals.
Out of \(114\) elements known so far, most of them are metals. The knowledge of metals and their uses has been known since ancient times. Copper, silver and gold coins have been used as currency in a different era. The use of iron metals in forming weapons is reported in history. Copper vessels have been used in domestic cookware for a long.
Metals are the electropositive elements that tend to lose one or more of their valence electrons attaining octet and form cations.
The metals usually have \(1,\,2\,{\rm{\;or\;\, 3}}\) electrons (some have \(4\) electrons) in their valence shell. Metals lose their valency electrons and form cations (positive ions) on gaining energy from an external source. e.g.,
The number of electrons lost by an atom of a metal to form the positive ion is called the valency of that metal. The ion of the metal carries the same number of unit positive charges. For example, sodium, magnesium and aluminium atoms lose \(1,\,\,2\) and \(3\) electrons respectively to form \({\rm{N}}{{\rm{a}}^ + },{\rm{M}}{{\rm{g}}^{2 + }}\) and \({\rm{A}}{{\rm{l}}^{3 + }}\) and show valency of \(1,\,2\) and \(3,\) respectively.
Non-Metals
Non-metals are the electronegative elements that tend to form anion (negative ions) by gaining one or more electrons.
The atoms of non-metals usually have \(4,\,5\,,\,6\,\,{\rm{or\;\, 7}}\) electrons in their valency shell. To gain a stable electronic configuration to attain octet, they tend to gain electrons and form anions (negative ions). e.g.,
\({\rm{N}} + \,3{\rm{e}} \to {{\rm{N}}^{3 – }}\)
\({\rm{O}} + \,2{\rm{e}} \to {{\rm{O}}^{2 – }}\)
The number of electrons gained by an atom of a non-metal to form the negative ion is called the valency of that non-metal. The ion thus formed carries the same number of unit negative charges. For example, an oxygen atom gains \(2\) electrons to form \({{\rm{O}}^{2 – }}\) ions. Therefore, the valency of oxygen is \(2\) and \({{\rm{O}}^{2 – }}\) ion carries two negative charges.
Position of Metals and Non-Metals in the Periodic Table
In the periodic table, metals are placed on the left-hand side, in the middle and at the bottom of the periodic table, whereas non-metals are placed on the extreme right-hand side of the periodic table. Hydrogen, although a non-metal but also resembles alkali metals, is an exception that is placed on the extreme left of the periodic table. Only a few metalloids exist, e.g., \({\rm{B}},{\mkern 1mu} \,{\rm{Si}},{\mkern 1mu} \,{\rm{Ge}},{\mkern 1mu} \,{\rm{As}},{\mkern 1mu} \,{\rm{Sb}},{\mkern 1mu} \,{\rm{Te}},\,{\rm{Po}}\) and \({\rm{At}}{\rm{.}}\)
Chemical Properties of Metals
The chemical properties of metals include the following reactions: (a) Reaction of metals with oxygen (b) Reaction of metals with water (c) Reaction of metals with dilute acids (d) Reaction of metals with salt solutions (e) Reaction of metals with chlorine (f) Reaction of metals with hydrogen
1. Reaction of Metals with Oxygen
Most of the metals react with oxygen \(({{\rm{O}}_2})\) in the air to form metal oxides.
The metal oxide formed is basic in nature. So, these oxides turn red litmus solution blue. Different metals react with oxygen at different temperatures. Some metals react with oxygen at room temperature, some react with oxygen on heating, and some react with oxygen only on strong heating.
Example 1: Reactive metals like sodium and potassium react with oxygen at room temperature to form oxides.
Example 2: Magnesium metal does not react with oxygen at room temperature. It burns with dazzling white light on heating in air forming magnesium oxide.
The oxides formed by most of the metals are basic in nature. For example, \({\rm{N}}{{\rm{a}}_2}{\rm{O}},\,{{\rm{K}}_2}{\rm{O}},\,{\rm{MgO,}}\,{\rm{CuO}}\) are basic in nature. Their reaction to water shows the basic nature of these oxides.
Sodium and potassium oxides are completely soluble in water, while magnesium oxide is partially soluble. The basic nature of hydroxides formed by the reaction of these oxides with water can be checked by red litmus solution.
Certain metal oxides like \({\rm{A}}{{\rm{l}}_2}{{\rm{O}}_3}\) and \({\rm{ZnO}}\) are amphoteric and show both acidic as well as basic behaviour. They react with both acids and bases to form salts.
3. Reaction of Metals with Water
Metals react with water to produce metal oxide and hydrogen gas. Water-soluble metal oxides dissolve in water to form metal hydroxide.
(ii) \({\rm{Metal}}\, + {\rm{Steam}}\,\, \to \,{\rm{Metal}}\,{\rm{oxide}}\, + {\rm{Hydrogen}}\)
The reactivity of each metal with water is different. Some reactive metals like sodium and potassium react with cold water, whereas some metals like magnesium do not react with cold water but react with hot water. Some metals do not react with water at all. They can react with steam. Certain metals like lead, copper, silver, gold and platinum do not show any reaction with water at any condition (neither water nor steam).
If the metal oxide is soluble in water, metal hydroxide and hydrogen gas are formed.
a. Sodium and potassium react violently with cold water. The reaction is highly exothermic, and the evolved hydrogen gas immediately catches fire.
(c) Calcium also reacts with cold water, but the reaction is not so violent. The reaction is also exothermic, but less heat is evolved, and the evolved hydrogen gas does not burn.
Under normal conditions, iron metal does not react with water. The reactions occur when steam is passed over red-hot iron, and the products are iron (II, III) oxides and hydrogen.
Note: Metals like copper, lead, silver, gold and platinum do not react with water at all.
4. Reaction of Metals with Dilute Acids
Some reactive metals like sodium, magnesium, aluminium, zinc and iron react with dilute acids to form salt and hydrogen gas. This is due to the displacement of hydrogen gas from dilute acids by the reactive metal.
Metals below hydrogen in the activity series of metals do not liberate hydrogen from acids. Still, they react with oxidizing acids (conc. \({{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}\,{\rm{or\, HN}}{{\rm{O}}_3}\) ) to form water, salt of the metal and the reduction products of the oxidizing acids. For example, copper reacts with dilute nitric acid to form water, copper nitrate and nitric oxide.
It is clear after studying the reaction of metals with oxygen, water and dilute acids that some metals are more reactive, and some are less reactive. When a more reactive metal is put in the salt solution of the less reactive metal, the less reactive metal is displaced from its salt solution by the more reactive metal.
Where, \({\rm{A}}\,\) is a more reactive metal than \({\rm{A}}\,\).
Only a more reactive metal can displace less reactive metal from its salt solution.
Example: When zinc granules are put in copper sulphate solution, its blue colour fades and becomes colourless. Also, a reddish-brown coating of copper is observed on the surface of zinc. This is because zinc is more reactive than copper and displaces copper from copper sulphate solution to form colourless zinc sulphate and copper deposited on the zinc surface.
All metals do not react with hydrogen. Only a few reactive metals like sodium, potassium, magnesium and calcium react with hydrogen to form metal hydrides.
The oxides formed by most of the non-metals are acidic in nature. For example, CO2 and SO2 are acidic in nature. Their reaction with water shows the acidic nature of these oxides.
Certain non-metal oxides like \({\rm{CO}},{\mkern 1mu} {\rm{NO}}\) and \({{\rm{N}}_2}{\rm{O}}\) are neutral in nature. These oxides do not show acidic or basic behaviour.
2. Reaction with Water
Unlike metals, non-metals do not react with water to evolve hydrogen gas. However, carbon reacts with steam at high temperatures to form a mixture of \({\rm{CO \;and\;}}\,{{\rm{H}}_2}\) known as water gas.
Non-metals do not react with dilute acids. They do not displace hydrogen from dilute acids. However, non-metals can be oxidized in the presence of conc. HNO3 and conc. H2SO4 due to the strong oxidizing nature of these acids.
4. Reaction of metals with salt solution
The reaction of non-metals with salt solutions is significant only in the case of halogens \(({{\rm{F}}_{\rm{2}}}{\rm{,}}\,{\rm{C}}{{\rm{l}}_{\rm{2}}}{\rm{,}}\,{\rm{B}}{{\rm{r}}_{\rm{2}}}\,{\rm{and}}\,{{\rm{I}}_{\rm{2}}})\) A more reactive halogen can displace a less reactive halogen from its salt solution.
Hydrogen chloride gas dissolves in water to form hydrochloric acid.
6. Reaction with Hydrogen
Non-metals also react with hydrogen to form hydrides. For example, sulphur and nitrogen react with hydrogen to form hydrogen sulphide and ammonia, respectively.
Difference between Metals and Non-metals Based on their Chemical Properties
The difference between metals and non-metals according to their chemical properties are as follows:
S.No
Reactionwith
Metals
Non- Metals
1.
Oxygen
Metal oxides are formed, which are generally basic in nature.
Non-metal oxides are formed, which are generally acidic in nature
2.
Water
Metal hydroxides are formed.
Generally, do not react
3.
Dilute acid
Metals more reactive than hydrogen displace hydrogen from dilute acids to form metal salts and hydrogen gas
Do not react with dilute acids
4.
Salt solution
More reactive metal displaces less reactive metal from its salt solution
Non-metal that is more reactive displaces less reactive non-metal from its salt solution
5.
Chlorine
Metal chlorides are formed which are ionic in nature
Non- metal Chlorides are formed, which are covalent in nature.
6.
Hydrogen
Reactive metals from ionic metal hydrides.
Covalent hydrides are formed
Summary
Metals and non-metals are necessary components of our daily existence. We can’t live without some non-metals, such as oxygen, and we’d have a hard time living without metals. Elements are distinguished as either metals or non-metals based on their properties. In this article, we have learned about the reaction of metal and non-metals with oxygen, water, acid, chlorides, and hydrogen.
FAQs on Chemical Properties of Metals and Non Metals
Q.1.What are the five chemical properties of metals? Ans: The five chemical properties of metals are: a. Metals form basic oxides. b. Metals displace hydrogen from water or steam. c. Metals above hydrogen in the reactivity series displace hydrogen from dilute acids. d. Metals behave as reducing agents. e. Metals form ionic hydrides.
Q.2. What are the five chemical properties of non-metals? Ans: The five chemical properties of non-metals are a. Non-metals form acidic or neutral oxides. b. Non-metals do not displace hydrogen from water or steam. c. Non-metals do not displace hydrogen from dilute acids and hence do not react with dilute acids. d. Non-metals form covalent chlorides. e. Non-metals behave as oxidising agents.
Q.3. How do the chemical properties of metals differ from non-metals? Ans:
Reaction with
Metals
Non-Metal
Oxygen
Metal oxides are formed, which are generally basic in nature.
Non-Metal oxides are formed which are generally acidic in nature.
Water
Metal hydroxides are formed.
Generally, do not react.
Dilute acid
Metals more reactive than hydrogen displace hydrogen from dilute acids to form metal salts and hydrogen gas.
Do not react with dilute acids.
Salt solution
Metal that is more reactive displaces less reactive metal from its salt solution.
Non-metal that is more reactive displaces less reactive-metal from its salt solution.
Chlorine
Metal chlorides are formed, which are ionic in nature.
Non-metal chlorides are formed which are covalent in nature.
Hydrogen
Ionic metal hydrides are formed by reactive metals.
Covalent hydrides are formed.
Q.4. Name a few metals and non-metals, which are in a liquid state at room temperature. Ans: Bromine is the only liquid non-metal at room temperature. Mercury is a liquid metal at room temperature.
Q.5.Why does iron corrode? Ans: The chemical reaction known as oxidation causes iron and iron alloys to rust. Oxidation happens when the iron is exposed to moisture or oxygen. Iron is transformed into iron oxide during this chemical process. Rusting is caused by both oxygen and moisture.
Q.6. Is colour a chemical property? Ans:No, physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include colour, density, hardness, and melting and boiling points. A chemical property describes the ability of a substance to undergo a specific chemical change.