Cations are positively charged ions formed when an atom loses an electron through ionization. The amount of energy required to do this is called the ionization energy.
Anions are negatively charged ions formed when an atom gains an electron. The energy in this process is called the electron affinity. Atoms have three main components: protons, electrons and neutrons. Protons are positively charged, and they occupy the central nucleus of the atom along with the neutrons. Electrons and protons have equal but opposite charges, and in the natural forms of elements, there are equal numbers of each in an atom.
This means elements are electrically neutral because the charges from the protons and electrons cancel each other out. An ion is a charged atom. If an atom gains an electron, the negative charge outweighs the positive charge, and the whole atom gains a negative charge. These ions are called anions. If the atom loses an electron, then there is more positive charge than negative charge, and the atom as a whole becomes a positively charged ion.
This is called a cation. In single use, dry cell batteries, zinc is commonly used as the anode whilst manganese dioxide is a popular choice for the electrolyte cathode. A zinc-carbon dry cell battery left and alkaline battery right.
In rechargeable batteries, such as many lithium-ion batteries, this chemical process is reversible and the internal structure different which allows the batteries to be recharged. Due to the ionic properties of salt water, scientists are now striving to exploit the ionic electricity-generating potential of salinity gradients where salt water and fresh water mix as a green source of energy generation for the future. What is a cation?
Meet The Author. Karen Steward PhD. Chosen for you. The difference is in the electrical charge. Anions have a negative charge, and cations have a positive charge. Electric charge is a basic property of elementary particles of matter protons , electrons , and neutrons. The protons in an atom have a positive charge, the electrons have a negative charge, and the neutrons have zero charge. In an ordinary atom, the number of protons equals the number of electrons, so the atom normally has no electric charge one way or the other.
An atom becomes negatively charged if it gains extra electrons, and it becomes positively charged if it loses electrons. We use the word ion to refer to atoms that have a charge one way or another, and we use the words cation and anion to specify whether the charge is positive or negative. Cations are positively-charged ions atoms or groups of atoms that have more protons than electrons due to having lost one or more electrons.
Anions are negatively-charged ions meaning they have more electrons than protons due to having gained one or more electrons. Cations are also called positive ions , and anions are also called negative ions. A cation is an ion with positive charge, which means it has more protons positively-charged particles than electrons negatively-charged particles.
Cations are formed when an atom loses one or more electrons: the loss of the negatively-charged electron s results in an overall positive charge. The reaction is as follows:.
Ionization is not limited to individual atoms; polyatomic ions can also be formed. When writing the chemical formula for an ion, its net charge is written in superscript immediately after the chemical structure for the molecule or atom. An alternative way of showing a molecule or atom with multiple charges is by drawing out the signs multiple times; this is often seen with transition metals.
Chemists sometimes circle the sign; this is merely ornamental and does not alter the chemical meaning. The Roman numeral designates the formal oxidation state of an element, whereas the superscripted numerals denotes the net charge.
The two notations are therefore exchangeable for monatomic ions, but the Roman numerals cannot be applied to polyatomic ions. However, it is possible to mix the notations for the individual metal center with a polyatomic complex, as demonstrated using the uranyl ion UO 2 as an example. It should be noted that it is possible to remove many electrons from an atom. The energy required to do so may be recorded in a successive ionization energy diagram. Boundless vets and curates high-quality, openly licensed content from around the Internet.
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