Elements And Compounds

Elements And Compounds

Introduction to Compounds and Elements

Chemistry is the study of the structures, physical properties, and chemical properties of material substances. It is very important to understand that all gases, liquids, and solids are not the same. All are different in terms of their composition. This is the reason why the classification of the matter is very important.

Chemically matter can be classified into 3 categories:

  • Elements
  • Compounds
  • Mixtures

Here we are going to discuss two categories of the matter: Elements and Compounds

What are Elements?

We can define elements as a species of atoms which have the same number of protons in their atomic nuclei. Although an element’s atoms have the same number of protons, they can have different numbers of neutrons and hence different masses.

Isotopes: When atoms of the same element have different numbers of neutrons, they are known as isotopes. As of now, there are 118 elements, of which the first 94 are naturally occurring while the remaining 24 are synthetic elements.

Elements are complete chemical substances which relate to a single entry in the modern periodic table. Elements consist of one kind of atoms only. They cannot be broken down into simpler fragments and can exist as either atom or as molecules. Elements are represented by symbols which are assigned by IUPAC. For example, Oxygen is represented by O, Aluminium is represented by Al, etc.

Types Of Elements

The elements are arranged in the periodic table and are split depending upon their groups as either metallic or non-metallic. Metallic is further classified into Main Group Metals, Transition Metals, and f-block metals. These are again further divided depending upon their properties.

Example Of Elements

Elements exist in their simplest form and cannot be broken down further. So, elements can exist in the form of ions, atoms, isotopes, molecules.

  • An example of an element is Nitrogen atom(N), Nitrogen gas (N2), Nitrogen ion(N3-) and Nitrogen isotopes (Nitrogen-13, Nitrogen-14, and Nitrogen-15).

Similarly, you could see other elements’ existence.

Examples of some commonly used elements and their chemical symbol:

Name of the element Chemical symbol
Hydrogen (H)
Boron (B)
Carbon (C)
Silicon (Si)
Sodium (Na)
Lead (Pb)
Platinum (Pt)

What are Compounds?

When two or more elements chemically combine in a fixed ratio by mass, the obtained product is known as a compound. Compounds can be defined as substances consisting of 2 or more different types of elements in a fixed ratio of its atoms. When the elements combine, some of the individual property of the elements is lost and the newly formed compound has new properties.

Chemical Formula: Compounds are represented by their chemical formula. A chemical formula is an information about the proportions of atoms that constitute a particular chemical compound.

The chemical formula of water is H2O which shows two atoms of hydrogen and one atom of oxygen have combined to form one molecule of H2O. The chemical formula for common salt is NaCl which shows one atom of sodium and one atom of chlorine combine to form one molecule of NaCl.

Types Of Compounds

Compounds can be classified into two types, molecular compounds, and Salts. In molecular compounds, atom binds each other through covalent bonds. In salts, it is held together with ionic bonds. These are the two types of bonds out of which every compound are made of.

Example Of Compounds

  • Example of compounds includes water (H2O), Hydrogen Peroxide (H2O2) etc. You could see water’s chemical formula, it says it has 2 atoms of Hydrogen combined with 1 atom of oxygen and in hydrogen peroxide, it has 2 atoms of hydrogen and two atoms of oxygen.
  • Similarly,  an example of salt would be the table salt (NaCl) which has 1 atom of sodium and one atom of chlorine.

Examples of some commonly used compounds and their molecular formula:

Compound Name Compound Formula
Alcohol C2H6O
Acetic Acid C2H4O2
Sulphuric Acid H2SO4
Ammonia NH3
Methane CH4
Nitrous oxide N2O
Salt NaCl

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Practise This Question

Who was the first scientist to define an element?