First 20 Elements of the Periodic Table: In the study of matter in chemistry, electron, proton, and neutron play a vital role to specify the element. Matter compulsorily has to have one or more than one proton in its nucleus to form an element. An Element is identified by the number of protons present in its nucleus. Elements in chemistry are generally considered the building blocks of matter. The nucleus of atoms of elements may have neutrons along with protons. Atoms of elements also have electrons that move around the atomic nucleus. When the number of electrons is changed then it forms an ion (whether positive or negative) but it doesn’t change the identity or features as an element. The compounds are formed by establishing the chemical bond to make the atoms of one element closer to that of another element. It is always advisable to memorize the first 20 elements of the periodic table for a better understanding of the chemistry concepts. These first 20 elements of the periodic table are available in day-to-day life also. In this article, you will know more about the list of the first 20 elements of the periodic table with their symbols, atomic number, and atomic mass.

List of the First 20 Elements of the Periodic Table

It is to be noted here that about 99% of the body mass of human beings is composed of 6 elements of these first 20 elements of the periodic table. The first 20 elements always help to have a good idea about the different groups of elements. The first 20 elements of the periodic table are present in our surroundings and these react chemically in our daily life also. Lithium, Beryllium, Sodium, Magnesium, Aluminium, Potassium, and Calcium are metallic elements in the first 20 elements of the periodic table while Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorous, Sulphur, Chlorine, and Argon are the non-metallic elements in the first 20 elements of the periodic table. There are only 3 elements as noble gases within the first 20 elements of the periodic table. These 3 noble gases are Helium (He), Neon (Ne), and Argon (Ar). Here the list of the first 20 elements of the periodic table with their atomic number, symbols, and atomic mass is mentioned below in the tabular form.

Atomic NumberElementSymbolAtomic Mass (u)
1HydrogenH1.008
2HeliumHe4.0026
3LithiumLi6.94
4BerylliumBe9.0122
5BoronB10.81
6CarbonC12.011
7NitrogenN14.007
8OxygenO15.999
9FluorineF18.998
10NeonNe20.18
11SodiumNa22.99
12MagnesiumMg24.305
13AluminiumAl26.982
14SiliconSi28.085
15PhosphorusP30.974
16SulfurS32.06
17ChlorineCl35.45
18ArgonAr39.948
19PotassiumK39.098
20CalciumCa40.078

Atomic Number of Element

The atomic number is defined as the number of protons available in the atomic nucleus of an element. The atomic number of an element is commonly known as the number of a particular element. It gives information about the number of protons present inside the atomic nuclei of a particular element. It also tells about the number of electrons orbiting around the atomic nucleus. For example, the atomic number of an element named sodium is 11. It denotes that the atomic nucleus of the sodium element has 11 proton particles and the nucleus is orbited by 11 electrons. It is to be noted that the atomic number is equivalent to the number of electrons. By checking the atomic numbers, the electron configuration of any element can be evaluated. The number of neutrons present in the atomic nucleus can not be measured by the atomic number of that element.

Atomic Mass of Element

The atomic mass is defined as the total mass of one atom of a particular element. The unit of atomic mass is the unified atomic mass unit (amu) and is symbolized by u. The standard atomic weight of an element gives the mean value of the atomic masses in the combined set of isotopes.

First 20 Elements of the Periodic Table: FAQs

Ans. The atomic number is defined as the number of protons available in the atomic nucleus of an element.

Ans. The atomic mass is defined as the total mass of one atom of a particular element.

Ans. About 99% of the body mass of human beings is composed of 6 elements of these first 20 elements of the periodic table. The first 20 elements always help to have a good idea about the different groups of elements.

Ans. Lithium, Beryllium, Sodium, Magnesium, Aluminium, Potassium, and Calcium are metallic elements in the first 20 elements of the periodic table while Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorous, Sulphur, Chlorine, and Argon are the non-metallic elements in the first 20 elements of the periodic table.

Ans. There are only 3 elements as noble gases within the first 20 elements of the periodic table. These 3 noble gases are Helium (He), Neon (Ne), and Argon (Ar).

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