Science Lesson #7: Basic Concept of Metals & Non-metals, Their Properties & Alloy Formation

Greetings fellow science Students and Teachers. You're welcome to science lesson #7. Today I want us to look at the concept of Metals & Non-metals, their properties and how some alloys are formed. You remember the concept of basic elements and I hope this would be very easier for our understanding in this concept. To recap, An Element is a pure substance which is made up of only one kind of atom and cannot be divided into any simpler substances. The smallest particle of this element is and atom which can take part in a chemical reaction. For instance, an atom of sodium (Na), an atom of chlorine (Cl) and an atom of aluminum (Al). Having got the concept of elements and atoms, we can easily grasp the concept of Metals and Non-metals.

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Metals are therefore atoms of elements which lose one or more electrons in the outermost shell electrons in order to be stable or readily to react with other elements during compound formation. So the cations of elements which would lose one or more electrons are therefore metals. Examples of Metals on the periodic table are : Aluminum (Al3+), Sodium (Na+), Magnesium (Mg2+), Beryllium (Be+), Potassium (K+), Lithium (Li+) and Calcium (Ca2+) if you consider the first twenty elements of the periodic table.

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Non-metals are atoms of elements which gain one or more electrons at their outermost shell elements or do not readily under go any lost of electrons and hence do not under go any reactions. Most of Anions form Non-metals. Examples of Non-metals are Nitrogen (N3-), Chlorine (Cl-), Fluorine (F-),Oxygen (O2-), Helium (He), Neon (Ne) Argon (Ar)

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Some physical properties of Metals

Knowing the physical & chemical properties of metals would really help us to study how metals behave so as to know how to handle them. The following are some of the basic physical properties of metals:

1• Most metals have polished surfaces. One of the practical example is a silver basin or bowl if placed on open place where the sun is shining, the sunlight reflects on it.

2• Metals are naturally harder. Most metals like Iron, Aluminum and Gold are very hard, and this explains why they are used for making the body parts of some machines.

3• Metals conduct electricity. For example Copper is used for electric Cables and most of the electronic gadgets simply because they conduct electricity.

4• Metals have high temperature

5• Metals have high melting points. It takes high temperature for certain metals like Iron to melt compared to Non-metals.

6• Most metals are malleable meaning they can be bent into different shapes. Steel benders and welders are able to mold metals into different shapes.

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Some chemical properties of metals

1• Metals react with atmospheric Oxygen. For example Iron rod react with atmospheric Oxygen to form hydrated Iron (III) as shown here: Fe + O -----> Fe₂O3

2• Metals react with water. Examples Sodium react with water to for sodium oxide and Hydrogen gas as shown:
Na + H₂O ---->Na₂O + H₂

3• Metals react with acids. Mg + H₂SO₄ ----> MgSO₄ + H₂

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Properties of Non-metals
1• Non-metals have dull surfaces

2• Non-metals don't conduct heat and electricity

3• Non-metals are brittle and easily break.

4• Non-metals can be solid liquid or gas.

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The formation of Alloys

Alloys are uniform formation of two or more metals, or metals and Non-metals together. For example a mixture of Iron and Carbon to form Steel. Brass is an alloy of Copper and Zinc. Bronze is an alloy of Copper and Tin. And Duralumin is an alloy of Aluminum and Copper.

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Properties of Alloys

1• Some alloys are harder than pure metals.

2• Alloys are resistance to corrosion and rusting. For instance stainless steel has ability to resist corrosion.

3• Alloys are often less reactive than pure metals.

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Uses of some alloys

1• Most alloys are used for set of cutleries such as knife, spoon and fork.

2• Alloys are used for making bells.

3• Alloys are mostly used in construction of bridges. Example, steel girders.

4• Most vehicles are constructed with Alloys know as steel frames.

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In Conclusion, the concept of Metals and Non-metals are very important especially knowing how they are formed, properties and uses. We therefore encourage our students to take the lesson very seriously. Thanks for your attention!

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