The elements are classified into metals and non-metals depending on their varying chemical and physical properties. Both metals and nonmetals are an essential part of our lives. We cannot imagine surviving without the nonmetals such as oxygen. Also, our survival would be complicated without the existence of the metals as well. Well, there is certainly a chemical science behind all these substances. However, in this article today, we will be dealing with only the topic of metals and what are the chemical properties of metals and nonmetals for class 8. So, here is a physical and chemical property of metals and nonmetals PDF that would help you learn about the properties of the metals.
Metals are known as the electropositive element wherein they tend to donate the electrons and form positively charged ions and become stable. Consider, for example,
Na ➝ Na+ + e-
Metals usually tend to possess certain distinguishing physical properties which make them easier for us to identify and classify.
The chemical properties of metals and nonmetals class 10 are as follows.
Some of the primary physical properties of metals are as follows.
The metals tend to possess lustre and a shiny or metallic appearance.
They are generally in the form of solids when present at room temperature.
Metals are generally very good conductors of both heat and electricity.
They are ductile and malleable.
Metals mostly tend to possess very high melting points.
Let us now take a look at the chemical properties of metals.
Reaction of Metal With Oxygen
Let us first discuss the chemical properties of metals react with oxygen.
Metals tend to react with oxygen and form the metal oxides. Metals tend to donate the electrons to oxygen to form these metal oxides. Consider, for example,
4K + O2 ➝ 2K2O
These metal oxides are usually basic, however, they can also turn out to be amphoteric. Amphoteric oxides refer that they are both acidic as well as basic in nature. Some metals such as sodium and potassium tend to react vigorously with the oxygen. When sodium or potassium gets exposed to air it tends to catch fire easily. Therefore, they are kept safe in kerosene.
Reaction of Metal With Water
Some metals also react with water and form a metal hydroxide while others do not react at all. The reactivity of metals with water differs from one metal to the other.
Metals such as sodium and potassium are highly reactive when they come in contact with the water. They react with water and form alkalis like the sodium hydroxide and the potassium hydroxide.
2Na + 2H2O ➝ Na(OH)2 + H2
Calcium also tends to react with water for forming calcium hydroxide compounds and hydrogen.
2Ca + 2H2O ➝ Ca(OH)2 + H2
On the other hand, magnesium and zinc do not tend to react with cold water. They, however, form their respective oxides when they are reacted with only hot water.
Mg + H2O ➝ MgO + H2
Iron is comparatively less reactive than elements like calcium, sodium, magnesium, potassium, and zinc. It does not react with hot and cold water, but reacts with steam and forms magnetic oxides.
3Fe + 4H2O ➝ Fe3O4 + 4H2
Reaction with Dilute Acids
Metals such as potassium, sodium, calcium and lithium tend to react vigorously with the diluted HCl and H2SO4 and form hydrogen and their respective metal salt
However, zinc, iron, magnesium, lead and tin do not vigorously react with the acids.
Mg + HCl ➝ MgCl2 + H2
Fe + H2SO4 ➝ FeSO4 + H2
Metals that fall below the hydrogen element in the reactivity series do not tend to react with the dilute acids. They do not displace hydrogen atom to form a bond with the non-metallic anion.
Reaction of Metal with Other Metal Salts
Metals that are relatively more reactive will readily tend to react with the less reactive metals. The more reactive metals tend to displace the less reactive metals from either their oxides, sulphides, or chlorides.
Zn + CuSO4 ➝ ZnSO4 + Cu
Metals are arranged in the periodic table according to their electrode potential. This is known as an electrochemical series which is as follows.
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1. What are the physical properties of Nonmetals?
Ans. The physical properties of the non-metals are as follows.
Non-metals are quite brittle and tend to break easily even when they are beaten. Examples of non-metals include phosphorus and sulphur.
They are not ductile and hence, cannot be drawn into thin wires.
They are poor conductors of both heat and electricity since they do not lose electrons for transmitting energy.
They can be in either state of matter at the room temperature, be it solids, liquids, or gases.
Non-metals are non-porous.
Non-metals are also transparent.
2. What are the chemical properties of Nonmetals?
Ans. The chemical properties of the non-metals are listed as follows.
Non-metals usually possess about 4 to 8 electrons in their valence shells.
They tend to accept or gain valence shell electrons.
When the non-metals are exposed to oxygen, they form their respective acidic oxides.
They tend to react with the hydrogen element to give their respective hydrides.
When exposed to a salt solution, more reactive non-metals displace the lesser reactive non-metals from the salt solution.
Non-metals are electro-negative and hence, have a higher electronegativity.
Non-metals are known to be good oxidising agents.
The non-metals do not tend to react with water.