What is the difference between an atom and an element? How are molecules different from atoms? I am often asked these questions in my sessions over and over again and so I finally decided to write a comprehensive post on them. Find answers to all your questions in this section that is designed to help students explore and understand the relationship between atoms, elements, molecules, compounds and mixtures in a manner that is simple and easy to understand. So, let’s begin!
  • What is an Atom?

    atoms-imgAll the matter in the universe is made of tiny particles called atoms.  There are 92 different kinds of atoms in nature. These 92 different atoms combine with one another to form different kinds of matter that we see in nature.

    Gold, for example, is made of only gold atoms. When matter is made of only one kind of atom, it is called an element. In the same way, silver is another element which is made of only silver atoms. Because there are 92 different kinds of atoms in nature, there are 92 different kinds of elements. Other examples of an atom are K (potassium) and Fe (iron).

  • What are Elements?


    The element is the fundamental substance that consists of only one type of atom. Elements consist of smaller particles and can be man-made or synthetic. Their arrangement in the periodic table is based on the number of protons in an increasing order. The atomic number of an element is indicated by Z. When atoms are arranged differently in an element having the same number of protons, you get different forms of an element. For example, both graphite and diamond are elements of carbon but they look very different from each other.

  • What is a Molecule?

    molecule-imgA molecule is the smallest unit of a chemical compound and it exhibits the same chemical properties of that specific compound. As molecules are made up of atoms jointly held by chemical bonds, they can vary greatly in terms of complexity and size. The oxygen we breathe has a molecular formula O2. Should we consider this as an element or compound? When two or more atoms of the same elements combine together, we call them Molecules. So, we call O2 as an oxygen molecule. In the same way, we find hydrogen molecules H2, chlorine molecules Cl2 and others in nature.

  • What is a Compound?

    compounds-imgThe chemical formula of water is H2O. Observe that, water is made of two hydrogen atoms and one oxygen atom. Here, two different elements, hydrogen and oxygen combine, giving rise to a new substance called water. Such substances, which are made by the combination of two or more kinds of elements are called Compounds. The atoms in a compound are chemically bonded and hence cannot be separated easily. Similarly, the chemical formula of carbon dioxide is CO2 and it is made up of two elements, carbon, and oxygen. Some other examples of compounds are table salt (NaCl), chalk (CaCO3)and water (H2O).

  • What is a Mixture?

    mixture-imgThe mixture is a substance made by the physical combination of two or more different elements or compounds. A mixture does not involve any chemical reaction. So, if you mix the magnetized powder with sand, you get a mixture that can be separated physically by means of a magnet. It can be composed of solids, liquids or gases and can be classified into 6 different categories – homogenous, heterogeneous, solutions, alloys, suspensions, and colloids.

    An evenly distributed mixture of water and ethanoic acid is called vinegar and can be termed as a homogenous mixture. When two or more substances are not evenly distributed in a mixture, like a blend of oil and water, the mixture is called heterogeneous. When salt is dissolved in water, you get a solution and when you combine two heterogeneous fluids containing solid particles that settle at the bottom, you get suspensions. Colloids are formed when one substance in a heterogeneous mixture is evenly dispersed throughout the other substance, example milk. Alloys are mixtures of one or more metals in a solid solution. Bronze, steel, and brass are common examples of alloys.

    I hope this helps all our students to clear their doubts about the differences between atoms, elements, molecules, and mixtures.

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24 Replies to “The difference between Atoms, Elements, Molecules, Compounds and Mixtures”

  1. Helpful but not realy clear on the different between atom and element, matter and substance, thy sound the same. For example all matter in the universe are made of atom, there are 92 atoms and 92 element in nature and example of element is gold, should we say that the same gold is an atom again then what is the difference between the two?
    Matter is made of atoms example of matter is liquid, solid and gases, are these same things not substances, explain please.

    1. Imagine going to an ice cream store. Let’s
      say that they have 30 different flavors of ice
      cream. Those are elements, the things that I
      have available to build my dessert from.
      The smallest amount of ice cream that the
      store will sell to me is a scoop. This is an
      atom. If I want, I can put two or more
      scoops of ice cream together. This is a
      molecule. If my molecule has more than
      one flavor of ice cream, I can call it a

  2. I can’t understand the difference between atoms and element .They both sounds same i.e. is neon an atom or element? I am of class 9th and tomorrow is my exam please clear my doubt……HELP!!!!

  3. Elements are the substances made up of only one kind of atom. Neon, Hydrogen, Oxygen are all different kinds of elements found in nature. An element is pure, consisting of only one kind of atom always.

    The number of atoms in an element may start from one, as in gases and may go up-to millions.

  4. I am confused between element molecule and compound
    Element is a substance made up of only one kind of atoms and compound is a substance made up of more than 2 kind of atoms ,then what is a molecule and isn’t 02 an element

    1. An element is a substance that is made entirely from one type of atom. For instance, see the periodic table where you can find all the 118 elements known to mankind.

      A molecule is a substance when where two or more atoms of the same element are joined together chemically. For instance, two atoms of Hydrogen (H) combines to form Molecular Hydrogen (H2). O2, N2, etc., are some other examples. (hence O2 is not an element, but ‘O’ is)

      Now, a compound is a substance that is formed from more atoms of different atoms or elements or molecules. For instance H20. Here, the molecular hydrogen (H2) combines with Oxygen atom (O) to form H20. Other examples can be CO2, CH4, etc.

        1. O is an element which consists of number of O atoms, where as O2 is a diatomic molecule. which means O in nature exists as O2. An element is made up of number of atoms of the same kind.

    1. I am new to Chemistry as well but to differentiate atom and element is quite simple. I am using it as Maths term.
      Atom = 1 single unit. Means only 1 unit of Helium is call atom.
      Element = 2 unit or more atom. Means 2 unit of Helium will become Helium gas.

      Do note that in this world what we learn in school is usually 3 state of matter: Solid,Liquid,Gas. We hardly can get 1 single unit in atom size. So if people ask you “Is Helium atom or element?” You need to clarify the question if she/he asking for 1 single atom or asking for 3 state of matter. Hope it helps.

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