What are Metals and Non-metals?
Metals and Nonmetals are the elements available around us. So, it is essential to know whether a particular element is a metal or nonmetal. Materials can be further divided into metals and nonmetals. The characteristic feature of metals such as aluminum and copper contains a high electrical and thermal conductivity, whereas nonmetals like sulfur and phosphorus metal are insulators. Elements are distinguished as either metals or nonmetals based on their properties.
Overview of Metals and Non-metals
An element is the simplest form of matter that cannot be split into or built from simpler substances by any ordinary chemical or physical method. Metals and nonmetals are essential parts of our lives. We can’t survive without some nonmetals such as oxygen, and without the existence of metals, our survival would be tough.
The majority of the periodic table elements are metals. These include transition metals, lanthanides, alkali metals, actinides, and alkaline earth metals. In a periodic table, metals are separated by nonmetals through a zigzag line starting from carbon, to radon. The elements between the two are selenium, phosphorus, and iodine.
The elements of these kinds and the elements to the right to them in the periodic table are nonmetals. Elements that are just to the left of the line are known as semimetals or metalloids. These will have the mixed properties of both metals and nonmetals.
Nonmetals are very few numbers in the periodic table. These are located on the right-hand side of the periodic table. Elements related to nonmetals are sulfur, carbon, phosphorus, all halogens, hydrogen, oxygen, nitrogen, selenium, and noble gases.
In the periodic table, nonmetals are located left to the halogens and right to the metalloids. Since halogens and noble gases are also nonmetals, these elements are often known to non-metals.
Chemical Properties of Metals
A few of the chemical properties of metals are listed below.
Usually, the density of metals is high.
Metals are ductile and malleable.
Metals form an alloy either with other metals or nonmetals.
Some metals like iron react with air and corrode.
Metals except lead are good conductors of heat and electricity.
In general, except for Mercury, all other metals are in a solid state at room temperature. But, Mercury belongs to a liquid state.
More metals produce metal oxide by burning in the oxygen of the air. Highly reactive metals react forcefully when they are burnt in oxygen.
Metals like potassium and sodium are stored in oil as they react with air in seconds. They’ll belong to highly reactive metals.
Less reactive metals like silver, gold, platinum and other related ones do not tarnish easily. They stay lustrous and shiny.
Metals produce hydrogen gas and metal oxide while reacting with water.
Soluble metal oxides dissolve in water and form metal hydroxide.
Not every metal reacts with water. However, highly reactive metals such as sodium and potassium react with water violently, and an exothermic reaction takes place where the hydrogen catches fire immediately.
When a metal reacts with an acid, hydrogen, and salt are produced
A metal generally displaces a less reactive metal in a metal salt solution.
Reactions of metals
Reaction of metal with oxygen: Metal oxides are formed when the metals react with oxygen. Metals usually donate the lone pair of electrons to the oxygen atom in order to form metal oxides. For instance,
4K + O2 → 2 K2O
Metal oxides are usually basic in nature but sometimes they also show amphotaric behaviour as well. Amphotaric is a condition where the metal oxides can act as both acidic and basic in nature. Few of the metals like potassium and sodium reacts vigorously with oxygen if kept in open atmosphere. This is the reason that they chatches fire when kept in open atmosphere. Therefore they are kept immersed in kerosine.
The reaction of metal with water: While some metals do not react, some of the metals react with water to form metal hydroxides. Thus the reactivity of water differes from metal to metal. The reactivity of sodium and pottasium is highly vigorous and they readly react with water to form their alkali such as sodium hydroxide and pottassium hydroxide.
2Na + 2H2O → 2NaOH + H2
Ca + 2H2O → Ca(OH)2 + H2
But magnisium do not react with cold water but reacts with hot water to form magnisium oxide.
Mg + H2O → MgO + H2
Because iron is less reactive as compaired to sodium, potassium, calcium and magnesium thus it does not react with cold or hot water but reacts with steam to form magnetic oxides.
3Fe + 4H2O → Fe3O4 + 4H2
Reaction with dilute acid: Metals like sodium, potassium, lithium and calcium react vigorously with dilute HCl and H2SO4 to form their metal salt and hydrogen. Magnesium, zinc, iron, tin and lead do not react vigorously with acids.
Mg + HCl → MgCl2 + H2
Fe + H2SO4 → FeSO4 + H2
The metals that are placed below the hydrogen in the reactivity series react with dilute acids. They cannot displace hydrogen to form a bond with a non-metal anion.
The reaction of metals with other metal salts: Metals that are more reactive will readily have less reactive metals. More reactive metal displaces the less reactive metal from its oxides, chlorides or sulphides.
Zn + CuSO4 → ZnSO4 + Cu
The arrangements of the metals according to the electrode potential of the metals in the electrochemical series are as follows:-
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Chemical Properties of Non-metals
Some of the chemical properties of nonmetals are listed below.
Nonmetals except gas carbon and graphite are poor conductors of heat and electricity.
Unlike metals, nonmetals are not ductile and malleable.
Nonmetals react more with metals compared to nonmetals.
Nonmetals usually react with other nonmetals at high temperatures.
Most nonmetals do not react with air at room temperature.
The only nonmetal is the white phosphorus that reacts with air to form its oxide by burning.
Nonmetals usually don’t react with water. Except for chlorine, chlorine dissolves in water to produce an acidic solution.
Nonmetals have a low density compared to metals.
Nonmetals do not form alloys. However, some like carbon, silicon, and phosphorus can form.
At room temperature, nonmetals exist in all states of matter.
Different nonmetals always have different reactions.
In the halogen family, the most reactive metal is chlorine i.e., Bromine (Br), Iodine (I), Chlorine (Cl), and Fluorine (F). The halogen family’s reactivity order is Cl > Br > I.
Thus, Chlorine (Cl) can displace Bromine (Br) and Iodine (I) from solutions of Iodides (NaI) and bromides (NaBr).
Ionic solids are formed when nonmetals containing high electronegativity react with alkaline earth metals and alkali.
Reactions of non-metals
Reaction with oxygen: When non-metals react with oxygen they form the non-metal oxides. The nature of the non-metal oxides are either acidic or netrual in nature.
When sulphur reacts with oxygen, we get sulphur dioxide.
S + O → SO2
When sulphur dioxide reacts with water it forms sulphurous acid.
SO2 + H2O → H2SO3
Reaction with water: Non-metals are non-reactive with water but reacts vigorously with the air. Therefore, many of the non-metals are immersed in water for storage. For example, phosphorus, which is one of the highly reactive non-metal reacts vigorously with air but when immersed with water prevents its contact with the atmosphere.
Reaction with acid: No non-metals ever react with acid.
Reaction with base: it is a very complex reaction when non-metals react with base. The reaction of chlorine with bases like sodium hydroxide gives products like sodium hypochlorite, sodium chloride as well as water.
Difference Between Chemical Properties of Metal and Nonmetals
FAQs on Chemical Properties of Metals and Non-metals
1. What are the main chemical properties of metals?
Metals exhibit several key chemical properties, primarily related to their tendency to lose electrons. The main properties are:
- Reaction with Oxygen: Metals react with oxygen to form metal oxides, which are typically basic or amphoteric in nature. For example, magnesium burns in air to form basic magnesium oxide (MgO).
- Reaction with Water: Reactive metals like sodium and potassium react violently with water to form metal hydroxides and hydrogen gas. Less reactive metals like iron react only with steam.
- Reaction with Dilute Acids: Most metals react with dilute acids (like HCl or H₂SO₄) to produce a metal salt and hydrogen gas. The reactivity varies based on the metal's position in the reactivity series.
- Displacement Reactions: A more reactive metal will displace a less reactive metal from its salt solution. For example, zinc displaces copper from a copper sulphate solution.
2. How do the chemical properties of non-metals differ from metals?
The chemical properties of non-metals are generally opposite to those of metals because they tend to gain or share electrons. Key differences include:
- Oxides: Non-metals react with oxygen to form acidic or neutral oxides (e.g., CO₂, SO₂), whereas metals form basic or amphoteric oxides.
- Reaction with Water: Non-metals do not react with water or steam to produce hydrogen gas.
- Reaction with Dilute Acids: Non-metals do not displace hydrogen from dilute acids.
- Reaction with Chlorine: Non-metals react with chlorine to form covalent chlorides (e.g., PCl₃), while metals form ionic chlorides (e.g., NaCl).
3. Why are some metal oxides, like aluminium oxide, considered amphoteric?
An oxide is called amphoteric if it can react with both acids and bases to form salt and water. Aluminium oxide (Al₂O₃) and zinc oxide (ZnO) are common examples. They show basic properties when reacting with an acid and acidic properties when reacting with a base. For example, aluminium oxide reacts with hydrochloric acid (an acid) and also with sodium hydroxide (a base), demonstrating its dual nature.
4. Why are highly reactive metals like sodium and potassium stored under kerosene oil?
Sodium and potassium are stored under kerosene oil as a safety precaution due to their extremely high reactivity. These metals react vigorously and exothermically with both oxygen and moisture present in the air. The reaction is so intense that the hydrogen gas evolved often catches fire. Kerosene is an inert liquid that creates a protective barrier, preventing the metal from coming into contact with air and water, thus stopping the reaction.
5. How does the reactivity series help predict the outcome of a displacement reaction?
The reactivity series is a list of metals arranged in order of their decreasing chemical reactivity. It is a powerful tool for predicting whether a displacement reaction will occur. The rule is simple: a metal higher in the series can displace any metal below it from its salt solution. For instance, since iron (Fe) is more reactive than copper (Cu), it can displace copper from a copper sulphate solution (CuSO₄). However, the reverse reaction will not happen; copper cannot displace iron from an iron sulphate solution.
6. Why do non-metals generally not react with dilute acids to produce hydrogen gas?
Non-metals do not react with dilute acids to produce hydrogen gas because they are electronegative elements, meaning they tend to accept or share electrons rather than donate them. For a substance to displace hydrogen from an acid, it must be more reactive than hydrogen and capable of donating electrons to the H⁺ ions in the acid, turning them into H₂ gas. Since non-metals cannot donate electrons easily, they cannot displace hydrogen, which is a characteristic chemical property of most metals.
7. What are some real-world examples that demonstrate the chemical properties of metals and non-metals?
Many everyday phenomena illustrate these properties:
- Rusting of Iron: This is a classic example of a metal (iron) reacting with oxygen and moisture to form its oxide (iron oxide or rust).
- Formation of Acid Rain: Non-metals like sulphur and nitrogen released from pollution react with oxygen in the air to form sulphur dioxide (SO₂) and nitrogen dioxide (NO₂). These acidic oxides dissolve in rainwater to form sulphuric acid and nitric acid, creating acid rain.
- Use of Antacids: Antacid tablets often contain basic metal compounds like magnesium hydroxide (Mg(OH)₂) or aluminium hydroxide (Al(OH)₃) that neutralize excess stomach acid (HCl), an application of the basic nature of metal hydroxides.
