How do ions differ from atoms

When electrons are added or removed, the neutral atom becomes an ion. If electrons are removed, the net charge of the ion is positive and it is known as a cation. When electrons are added, the net charge of the ion is negative and it is known as an anion. Download instructions, a grid and prompt cards to play atoms, molecules and ions 4-in-a-line from the Education in Chemistry website: rsc. Atoms, molecules and ions are all examples of particles that students might meet at 11— But these terms are often used incorrectly in the media and everyday language leading to students of all ages being confused as to which is the correct term to use.

The idea of the world being made of tiny particles is an ancient one. You could start the exploration of atoms with the ideas of Democratus BC , who believed that all matter in the universe was made up of tiny, indivisible, solid objects.

Different spheres made up the different elements. One of the key problems for students learning about atoms, is that atoms are small. Really, really small. This makes it difficult for students to conceptualise atoms as they cannot be seen, or touched, or investigated directly. A good starting point to introduce atoms and illustrate their small size is to ask students to break up a piece of graphite the element carbon into as many small pieces as they can.

No matter how many pieces the students break the graphite into, they will never get a single carbon atom. You can challenge higher attaining students to measure the size of an individual atom using this experiment from Practical physics.

You can challenge higher attaining students to measure the size of an individual atom using this experiment from Practical physics bit.

When atoms combine, molecules are formed. For a few elements, when atoms of that element combine, a molecule of that element is formed eg H 2 and O 2. When atoms of some different elements combine, a molecule of a compound can form, eg H 2 O. How to teach elements and compounds , in the 11—14 series, describes different strategies for teaching elements and compounds and the common misconceptions students may hold.

How to teach elements and compounds rsc. Particle diagrams can be used to help the students visualise the difference between an atom, a molecule of an element and a molecule of a compound. In fact even Dalton in the s proposed a series of diagrams to represent the elements and compounds known at the time. Atom vs Ion. An Atom is the smallest and an indivisible unit of matter. Ions are Atoms where the protons and the electrons are not equal.

Ions would therefore be either positive or negatively charged. An Atom is composed of Protons, Neutrons and electrons. The protons and neutrons form the nucleus of the Atom while electrons surround the nucleus. An Atom remains electrically neutral till the number of electrons and protons are equal. An Atom with unequal number of electrons and protons is electrically charged and called an Ion. If the number of electrons is more than protons it is called an Anion and if the protons are more than electrons it is called Cation.

An Atom is the smallest particle of an element which can take part in a chemical reaction whereas the Ions are not capable of taking part in chemical reactions. Ions can, however, exist independently in a solution, whereas, Atoms may or may not be able to exist independently. The outermost shells of Atoms may or may not satisfy the duplet or octet rule of chemistry while the Ions will have duplet or octet in their outermost shells.

This particular resource used the following sources:. Skip to main content. Atoms, Molecules, and Ions. Search for:. Learning Objective Compare the different classes of ions. Key Points Ions are formed when the number of protons in an atom does not equal the number of electrons. If more protons are present, the ion is positive and is known as a cation; if more electrons are present, the ion is negative and referred to as an anion.

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