# Periodic Elements with their Symbols and Atomic Numbers

Here you can find  Periodic elements, with their properties. By the end of 18 century, only 28 elements are known. By 1870, 65 elements. By 1925, 88 elements. At present, 118 elements are known to us.

## Do you know about Periodic Elements?

A table showing the systematic arrangement of elements is called the periodic table. Basically, it is based on the periodic law which states that the elements are arranged in order to increase their atomic numbers. The periodic table is one of the most important tools in chemistry. If you make our chemistry strong, it is very useful for understanding and predicting the properties of elements.

If you know the physical and chemical properties of any element in a group, you can also predict the physical and chemical properties of the other elements present in the same group. we can use the modern periodic table to predict the reactivity of elements with their atomic structures.

### Atomic symbol:

All the elements in the periodic table are represented by symbols, which are abbreviations for the name of the element. A symbol of an element can be one letter or two letters.

### Atomic number:

It is the number of protons present in the nucleus of an atom. It is represented by the symbol ”Z”. Remember that all the atoms of an element have the same number of protons in their nucleus, they have the same atomic number. No atom has the same atomic number. You can also say the atomic number is the identification number of an atom. For example, all atoms in lithium have 3 protons. their atomic number is 6. Similarly, Sulphur has 16 protons so its atomic number is 16.

### Atomic mass:

It is the number of protons and neutrons present in the nucleus of an atom. It is represented by the symbol ”A”. The formula to calculate the atomic mass is A = Z + n. Where n is the number of neutrons. In the whole periodic table, only a single atom of hydrogen has no neutrons. It has 1 proton and no neutron in its nucleus. Its atomic mass is A = 1 + 0 = 1. Nitrogen has 7 protons and 7 neutrons, hence its mass number is 14.

#### How many protons and neutrons are there in an atom having A = 133 and Z = 55?

A = 133

Z = 55

Number of protons =?

Number of neutrons =?

Number of protons = Z = 55

Number of neutrons = A – Z

Number of neutrons = 133 – 55 = 78

### Valency:

Valency tells how maximum bonds are formed by an element. It is the combining capacity of an element with other elements. It is also defined as the number of electrons lost or gained by an atom to form a cation or anion respectively. Some elements like copper, Mercury, etc show more than one valency is called variable valency.

#### Why is the periodic table important?

The periodic table is important because it can be utilized to determine the properties of elements, even those that have not yet been found. Columns and rows demonstrate elements that share similar properties. Chemical equations are also balanced by the periodic table element properties are evident and straightforward by making trends via the periodic table.

#### How do you explain the periodic element?

The 118 known elements are arranged in a systematic order in the modern periodic table. These elements are organized in order of increasing atomic number, or the number of protons in an atom’s nucleus, which typically corresponds with increasing atomic mass, from left to right and top to bottom. The periodic table’s horizontal rows are known as periods, and each period number represents the number of orbitals that each element in that row has.

For example, elements in the first period have one atomic orbital where electrons spin; those in period 2 have two; those in period 3 have three; and so on and so forth until period 7. The atomic elements that have the same number of valence electrons, or electrons in the outermost orbital shell, are represented by the columns, or groups, on the periodic table.

#### What are the atomic number and atomic mass?

##### Atomic number

The atomic number is defined as the total number of protons in the nucleus of an atom that is the atomic number. It is symbolized by Z.

##### Mass number

The sum of neutrons and protons is equal to the mass number of an atom.

For example, the carbon atom has 6 protons and 6 neutrons so its mass number is 12 and its atomic number is 6. Always keep in mind number of protons same and the number of neutrons can change in the atoms of an element.

#### What is valency with example?

Valency is the measure of how many electrons an atom gains or loses to complete its outermost shell. By completing their outermost shell, or octet, the atoms become stable (8 electrons in the outmost shell).

##### Example:

Electronic configuration 2, and 6 is present in the oxygen. This means that it has 6 electrons in its outermost orbit or shell. In order to complete the octet, it will therefore require two extra electrons. So its valency is two.

#### How do you find valency?

• Eight electrons can fit inside a valence shell at most.
• As a result, a valence shell’s electron count might range from 1 to 8.
• Now imagine that an atom contains 1, 2, or 3 valence electrons.
• It is simpler for them to lose 1, 2, and 3 electrons from the valence to complete an octet, respectively.
• Valency of atom losing 1 electron = 1
• Valency of atom losing 2 electrons = 2
• Valency of an atom losing 3 electrons = 3

#### What is meant by oxidation state?

The total amount of electrons that a specific atom in a chemical reaction can accept, give, or share with any other atom is known as its oxidation state. The oxidation state not only represents anything numerically but also shows whether an atom is negatively or positively charged.

#### How do you find the oxidation state?

The following guidelines can be used to assign an oxidation state to a specific element or molecule.

• Any element that is in a free state has a zero oxidation number.
• For monoatomic ions, the oxidation number is always equal to the ion’s corresponding net charge.
• The oxidation state of the hydrogen atom (H) is 1. However, it displays an oxidation number of -1 when coupled with an element that has a lower electronegativity than it.
• Most of the substances that oxygen is found in have an oxidation of -2. But the oxidation number of oxygen in peroxide is -1.
• The oxidation state of all alkali metals (group 1 elements) in their compounds is one.
• An oxidation state is two present in all group 2 elements known as alkaline earth metals.
• Halogens (group 17 elements) are given an oxidation number of -1 in compounds composed of two elements.
• For neutral compounds, the total oxidation number of the atoms that make up the chemical is zero.
• When polyatomic ions, their net charge is equal to the total oxidation numbers of the atoms that make them up.

## Ligands and its Types | Coordination Compounds

To understand the concepts of ligands, first, you need to know about the introduction of coordination compounds. In…

## Electrophilic Substitution Reaction

An electrophilic substitution reaction is a type of reaction in which a functional group is replaced by an…

## Racemic Mixture | How to resolute Racemate?

Before going to discuss racemic mixture first of all we have to know important term enantiomers. Enantiomers: The…

## Effective Atomic Number | How To Calculate EAN

Before we discussed the effective atomic number or EAN and how to calculate it, it’s very important to…