118 Elements, Their Symbols and Atomic Numbers - Need of Assigning Symbol to Elements, Methodology of Giving Symbols, IUPAC System of Nomenclature, Practice Problems, FAQs

We all are fond of watching international cricket games. Have you ever seen the scoreboard? It usually looks like this.

Here, we can observe a lot of short forms such as b,w, wd, nb,b, lb and all these actually stand for bowled, wicket, wide,no-ball, bye, and leg-bye respectively. These short forms are used to present all the data of that particular match on the scoreboard.

Similarly, we also use symbols for chemical elements to arrange all elements with their atomic number and atomic weight in the periodic table. Let’s see why and how elements are symbolized

TABLE OF CONTENTS

• Need of Assigning Symbols to Chemical Elements
• Methodology of Giving Symbols
• Atomic Number
• IUPAC Nomenclature of Elements with Atomic Number Greater Than 100
• List of Elements and Their Symbols
• Practice Problems
• Frequently Asked Questions - FAQ

Need of assigning symbols to chemical elements

The periodic table of elements which is widely used in the field of Chemistry is used to quickly refer some important physical parameters of chemical elements as they are arranged in a manner that displays periodic trends of their chemical properties also. However, the Periodic Table generally displays only the symbol of the element and not its entire name.

Imagine a table with elements mentioned with their full name. It would have been a mess, just the same way any chemical reaction is written with a full name instead of its corresponding symbols. It is handy and simpler to use symbols rather than full names

Chemical elements are denoted by symbols, which often include one or two characters. Some symbols are labelled briefly using three letters and typically represent new elements having atomic number greater than 100. A chemical symbol also called an element symbol, is a letter or pair of letters used to represent a chemical element. The chemical symbol for an element is used when writing the chemical formula for a molecule, or when writing a chemical equation because it is shorter and easier.

Methodology of Giving Symbols

The Periodic Table of elements is broadly used in the field of Chemistry to get an idea of chemical elements which are arranged in a way that shows periodic trends in the chemical properties of the elements. However, the periodic table usually displays just the symbol of the element and not its complete name.

Elements symbols have been derived from many sources. Some are directly from the English name, some from their Latin roots, etc. We shall see such different sourcing of symbols now.

1. From their English Name

The majority of elements are represented by symbols based on their English names. A chemical symbol is a one- or two-letter element designation. O for oxygen, and Zn for zinc are some examples of chemical symbols. A symbol's first letter is always capitalised. If there are two letters in the symbol, the second letter is lowercase.

2. From their Latin Name

There are some symbols of elements that have Latin roots. An example of it is silver which is denoted by Ag which is derived from its Latin name "Argentum". Another such example would be the symbol 'Fe' which is used to represent iron and can be related to the Latin word for iron, "Ferrum".

3. From the country of discovery

Elements like Americium, Germanium, Europium, and Francium, are named after their place of discovery.

4. In the name of Planets and Stars

Some elements got their names from the names of planets or stars too. Look at the elements Mercury, Neptunium, Uranium, Plutonium, Helium.

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5. In the Name of the Discoverer of the Elemen or in honour of a scientist.

Some elements were named after the famous scientist, like,

Bohrium, Curium, Einsteinium, Mendelevium and Rutherfordium

6. Elements are also named based on their behaviour!

Hydrogen got its name because it forms water.

Rubidium is named so due to its deep red colour.

Due to the faint glow in the air, phosphorus got its name.

Atomic Number

Knowing the precise composition of elements is necessary to comprehend the concepts of atomic number and valency. A single sort of atom makes up an element. The smallest indivisible unit of matter is an atom. It is made up of protons, neutrons, and electrons. A positive charge characterises protons. Since neutrons are neutral, they are free of charge. The nucleus is surrounded by negatively charged electrons.

The atomic mass of an element is calculated as the sum of its protons and neutrons. The quantity of electrons orbiting an element's nucleus determines its chemical characteristics.

The total number of protons in an atom's nucleus is its atomic number. The letter Z is used to represent it. The atomic number, or fixed number of protons in an atom, is used to identify an element. The atomic number is hence distinct for each element. For this reason, understanding atomic numbers is crucial to comprehending the chemistry of elements.

IUPAC Nomenclature of Elements with Atomic Number Greater Than 100

Following rule should be remembered for the IUPAC nomenclature of an element with an atomic number greater than 100.

1. The name of the element is directly derived from the atomic number by using following numerical roots:

2. Element symbols can be written by initial letters of numerical roots.
3. As per the atomic number, IUPAC Name can be derived by adding word roots and ending by ‘ium’.

List of Elements, Their Atomic Number and Their Symbols

The complete list of elements in the periodic table is given below -

Practice Problems

Q1. What is the symbol of the element Sodium?

1. S
2. Sd
3. Na
4. Nd

Answer: (C)

Solution: The chemical abbreviation for sodium was first published in 1814 by Jöns Jakob Berzelius in his system of atomic symbols, and is an abbreviation of the element's New Latin name Natrium, which refers to the Egyptian natron, a natural mineral salt mainly consisting of hydrated sodium carbonate.

Q2. The period number of any element corresponds to its highest:

1. Azimuthal Quantum number
2. Principal Quantum Number
3. Magnetic Quantum Number
4. Spin Quantum Number

  B.

Principal quantum number corresponds to the number of shells of an atom and it is represented by n and the highest value for an element corresponds to the period number of an element.

Q3. How many elements does the shortest period consist of?

1. 2
2. 4
3. 8
4. 6

Answer: A.

Shortest period is the first period having two elements i.e., Hydrogen and Helium.

Q4. How are the elements in the periodic table arranged?

1. Increasing electronegativity
2. Increasing atomic number
3. Increasing order of density
4. Increasing order of the number of neutrons

Answer B

Increasing atomic number forms the basis of the modern periodic table.

Frequently Asked Questions - FAQs

Q1. Who gave the modern periodic law?
Answer: In 1869, Dmitri Mendeleev and Lothar Meyer established the periodic law independently, but both defined periodicity in terms of atomic mass. It was Moseley, who observed regularities in the characteristic X-ray spectra of the elements when their frequencies were plotted against their respective atomic number. So the modifications done in the periodic law in modern times (i.e, the physical and chemical properties of the elements are periodic functions of their atomic numbers) can well be attributed to Moseley.

Q2. How do periodic trends relate to periodic law?
Answer: Periodic trends give similar patterns in the periodic table showing us the various aspects of an element such as electronegativity, atomic radius, or ionising power. The periodic law tells us that when grouped by atomic number, certain properties of elements occur periodically.

Q3. What is an atomic number?
Answer: The atomic number of an element is equivalent to the total number of protons in the nucleus of the atoms of that element.

Q4. Why silver is symbolized as Ag?
Answer: Silver's element symbol Ag, is from the Latin word Argentum meaning silver.

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