Several elements can be found on Earth. 98 elements have been identified from the Earth’s crust. They are listed on the periodic table and grouped according to their properties.
In this article, we will discuss the concept of elements and compounds, their types and other related topics.
What are Elements?
First, we need to know where the term element came from. The term element was first used by Robert Boyle in 1661, and Antoine Laurent Lavoisier was the first to define the element in a useful definition. According to Antoine, “An Element is a basic form of matter which cannot be broken down into simpler form by chemical reaction.”
Types of Elements
Elements can be categorised into three types:
Metals: They can be defined as substances that are characterised by high thermal and electrical conductivity as well as by malleability, ductility, and high reflectivity of light. Some examples of metals are gold, iron, aluminium, etc. Mercury also comes under metals, but it is the only metal in liquid form at room temperature.
Non-metals: They can be defined as elements that have low strength, low density and are poor conductors of electricity and heat. They have the tendency to form acidic compounds. They are available in various colours compared to the metals, which are available in only yellow-silver colours. Some examples of non-metals are iodine, oxygen, hydrogen, etc.
Metalloids: They are elements that have intermediate properties between typical metal and nonmetal. Some of the examples of metalloids are boron, germanium, antimony, etc.
In the periodic table, elements are organised according to the atomic number, grouped based on similar properties.
What are compounds?
Compounds are substances composed of two or many elements consisting of atoms. These compounds are held together in a fixed ratio by chemical bonds. Elements found on Earth combined with the other elements to form chemical compounds. For example, NaCl (Salt) is formed by combining Na, i.e. Sodium and Cl, i.e. Chloride.
- These compounds can be held together by ionic or covalent bonds.
- These chemical compounds consist of unique properties which differ from the element’s individual properties.
- These compounds have a defined structure.
Covalent Bond: These bonds share two or more electrons between the atoms. These bonds have physical properties like melting points and electrical conduction. Carbon monoxide and methane are examples of covalent bonds. Covalent bond mostly occurs between nonmetals or similar elements.
Ionic Bond: It is another type of bond. It occurs between the two atoms with a considerable difference in electrons. This bond occurs between the non-metal and metal, where metal works as an electron donor and non-metal works as an adopter.
In an ionic bond, more than one electron can be donated and adopted. Kl, NaCl, MgCl2
are examples of the ionic bond.
Difference between Elements and Compound
Point of difference | Element | Compound |
Definition | An element is a pure substance made of a similar kind of atom | A compound consists of atoms of different elements combined chemically in a fixed ratio |
Capability to break down | It cannot be broken down | It can be broken down by chemical reaction |
Presentation | They are represented by their symbol | They are represented by their formula |
Types | There are three types of elements i.e. metal, non-metal, and Metalloids | There are several types of a compound like molecular, ionic, intermetallic, and complex compounds |
Composition | Elements consist of only one type of atom, with each atom containing a similar atomic number | Compounds consist of different elements bonded by a chemical reaction in a fixed ratio. They have only one type of molecule |
Examples | Iron, Silver, Copper are some examples of elements | Hydrochloric acid (HCl), Carbon Monoxide (CO), Sugar (C12H22O11) are some of the examples of the compounds |
Conclusion
Elements can be defined as the simpler forms of matter which cannot be broken down further. There are 118 elements listed on the periodic table. Compounds are the product of the bonding of two or more elements. They can be bonded either by covalent or ionic bonds to form a chemical compound.