First 20 Elements of Periodic Table – Name and Symbols

Elements are the purest form of matter which has only one type of atoms. There are total 118 elements found till date. These elements are arranged in a tabular form in increasing order of atomic number such that elements with common properties are arranged together. This tabular arrangement of elements is called Periodic Table of Elements. In this article, we will learn first twenty elements with atomic number 1 to 20 along with their properties.

What are the First Twenty Elements?

The first twenty elements in the periodic table are as follows: Hydrogen (H), Helium (He), Lithium (Li), Beryllium (Be), Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), Neon (Ne), Sodium (Na), Magnesium (Mg), Aluminum (Al), Silicon (Si), Phosphorus (P), Sulfur (S), Chlorine (Cl), Argon (Ar), Potassium (K), Calcium (Ca). Let’s discuss the elements listed above in detail.

Table for First 20 Elements

The first 20 elements are tabulated in increasing order of their atomic number along with their symbols and atomic masses:

Atomic number	Names of elements	Symbols	Atomic masses
1	Hydrogen	H	1.008
2	Helium	He	4.0026
3	Lithium	Li	6.94
4	Beryllium	Be	9.0122
5	Boron	B	10.81
6	Carbon	C	12.011
7	Nitrogen	N	14.007
8	Oxygen	O	15.999
9	Fluorine	F	18.998
10	Neon	Ne	20.18
11	Sodium	Na	22.99
12	Magnesium	Mg	24.305
13	Aluminum	Al	26.982
14	Silicon	Si	28.085
15	Phosphorus	P	30.974
16	Sulphur	S	32.06
17	Chlorine	Cl	35.45
18	Argon	Ar	39.948
19	Potassium	K	39.098
20	Calcium	Ca	40.078

Elements 1 to 10

The first ten elements in the periodic table are as follows: Hydrogen (H), Helium (He), Lithium (Li), Beryllium (Be), Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), Neon (Ne). Let us discuss each of these in detail one by one.

Hydrogen (H)

• Hydrogen is the first element in the periodic table with atomic number 1 and symbol H.
• It is classified as a nonmetal and exists as a gas at room temperature.
• Hydrogen has only one electron in its atom.
• Physical properties of hydrogen include a melting point of -259°C, a boiling point of -253°C, and a density of 0.090 g/L as a gas at 0°C and 1 atm pressure.

Helium (He)

• Helium is a chemical element with the symbol He and atomic number 2.
• It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas.
• Helium has unique properties such as a low boiling point, low density, low solubility, high thermal conductivity, and inertness.
• Physical properties of helium include a melting point of 0.95 K (-272.2°C), a boiling point of 4.222 K (-268.928°C), and a density of 0.1786 g/L at STP.

Lithium (Li)

• Lithium is a chemical element with the symbol Li and atomic number 3.
• It is a soft, silvery-white alkali metal that reacts vigorously with water.
• Lithium is commonly used to treat mood disorders such as mania and bipolar disorder.

Beryllium (Be)

• Beryllium is a chemical element with the symbol Be and atomic number 4.
• It is a steel-grey, strong, lightweight, and brittle alkaline earth metal.
• This silvery-white metal is relatively soft and unaffected by air or water, even at high temperatures.

Boron (B)

• Boron is a chemical element with the symbol B and atomic number 5.
• It is a metalloid that is not found naturally on Earth.
• Boron plays important role in osteogenesis, where its deficiency can negatively impact bone development and regeneration.

Carbon (C)

• Carbon is a chemical element with the symbol C and atomic number 6.
• It is a nonmetallic, tetravalent element, meaning its atoms can form four bonds.
• Carbon is solid at room temperature and plays a fundamental role in various forms of life, as well as in industry and technology.

Nitrogen (N)

• Nitrogen is a chemical element with the symbol N and atomic number 7.
• It is a nonmetal and the lightest member of group 15 of the periodic table.
• Nitrogen is a colorless, odorless, tasteless gas that is the most plentiful element in the universe
• Nitrogen is also involved in numerous biological activities and has significant impacts on ecosystems.

Oxygen (O)

• Oxygen is a chemical element with the symbol O and atomic number 8.
• It belongs to the chalcogen group in the periodic table and is a highly reactive nonmetal.
• Oxygen is an essential component of the Earth’s atmosphere, constituting about 21%.
• This colorless, odorless, and tasteless gas is crucial for living organisms as animals use it and convert it to carbon dioxide.

Fluorine (F)

• Fluorine is a chemical element with the symbol F and atomic number 9.
• It is the lightest halogen and exists as a highly toxic, pale yellow diatomic gas at standard conditions.
• Fluorine is known for its extreme reactivity, reacting with almost all other elements except for light inert gases like helium and neon.

Neon (Ne)

• Neon is a chemical element with the symbol Ne and atomic number 10.
• It is the second-lightest noble gas after helium. Like other noble gases, neon is colorless and odorless.
• It glows reddish-orange in a vacuum discharge tube.

Elements from 11 to 20

The elements from 11 to 20 in the periodic table are as follows: Sodium (Na), Magnesium (Mg), Aluminum (Al), Silicon (Si), Phosphorus (P), Sulfur (S), Chlorine (Cl), Argon (Ar), Potassium (K), Calcium (Ca).

Sodium (Na)

• Sodium is a chemical element with the symbol Na and atomic number 11.
• It is a soft, silvery-white, highly reactive metal that belongs to the alkali metal group of the periodic table.
• Sodium is predominantly found in the form of sodium chloride (NaCl), which is commonly known as table salt. .

Magnesium (Mg)

• Magnesium is an essential mineral with atomic number 12 and atomic mass 12.
• It belongs to alkaline earth metal group i.e. group 2 of periodic table.
• It is important for normal bone structure and can be obtained from diet or supplements.

Aluminum (Al)

• Aluminum is a chemical element with the symbol Al and atomic number 13.
• It is a silvery-white, lightweight, non-magnetic, ductile metal that is the most abundant metal in the Earth’s crust.
• Aluminum is a post-transition metal in the boron group, and it primarily forms compounds in the +3 oxidation state.
• This metal is known for its high strength-to-weight ratio, making it a popular choice for various applications, such as aircraft construction, automobiles, and building materials.

Silicon (Si)

• Silicon is a chemical element with the symbol Si and atomic number 14.
• It is a hard, brittle crystalline solid with a blue-grey metallic luster, classified as a nonmetal and semiconductor.
• It is the second most abundant element in the Earth’s crust, making up 27.7%.
• Silicon plays a significant role in semiconductor industry due to its unique properties and versatility.

Phosphorus (P)

• Phosphorus is a chemical element with the symbol P and atomic number 15.
• It is a mineral that makes up about 1% of a person’s total body weight, being the second most abundant mineral in the body.
• Phosphorus exists in two major forms: white phosphorus and red phosphorus.

Sulphur (S)

• Sulfur is a chemical element with the symbol S and atomic number 16.
• It is abundant, multivalent, and nonmetallic.
• Sulfur atoms typically form molecules with other elements, and under normal conditions, sulfur exists as a yellow crystalline solid.
• Sulfur has “rotten egg” smell when in certain compounds.

Chlorine (Cl)

• Chlorine is a chemical element with the symbol Cl and atomic number 17.
• It is a yellow-green gas at room temperature and is extremely reactive, making it a strong oxidizing agent.
• Chlorine is two and a half times heavier than air and becomes a liquid under high pressure.

Argon (Ar)

• Argon is a chemical element with the symbol Ar and atomic number 18.
• It is a noble gas, meaning it is primarily found in its elemental form and does not react with most other elements.
• Argon is the third most abundant gas in Earth’s atmosphere, making up about 1% of the air we breathe.
• This element is colorless, odorless, and non-toxic.

Potassium (K)

• Potassium is a chemical element with the symbol K and atomic number 19.
• It is classified as an alkali metal and belongs to Group 1 of the periodic table.
• Potassium has a silvery-white appearance and is soft enough to be easily cut with a knife.
• Potassium has a melting point of 336.53 K (63.38°C or 146.08°F), a boiling point of 1032 K (759°C or 1398°F), and a density of 0.89 g/cm³.

Calcium (Ca)

• Calcium is a chemical element with the symbol Ca and atomic number 20.
• It belongs to Group 2 of the periodic table as one of the alkaline-earth metals.
• Calcium is a solid at room temperature and is the fifth most abundant element and the third most abundant metal in the Earth’s crust.
• Calcium has an atomic weight of 40.078, a melting point of 1115 K (842°C or 1548°F), a boiling point of 1757 K (1484°C or 2703°F), and a density of 1.54 grams per cubic centimeter.

What Does an Element’s Atomic Number Tell Us

Atomic Number of an element tell us about the number of proton in the nucleus of the atom. Proton is the positively charged species found in the nucleus of the element. The atomic number of element is unique for each element. This means the number of protons in different element is different. We often get confused that atomic number is the number of electrons but it is wrong. Atomic number of an element is equal to number of electrons in an element in its ground state only. This is because elements can lose, gain or share electrons for their stability but they can’t share protons. Hence, atomic number of an element tell us about the number of protons in the element which ultimately tell about the unique property of each element.

Why are Sodium and Potassium denoted by ‘Na’ and ‘K’ Respectively

Potassium and Sodium are denoted by K and Na respectively referring to their Latin name which is Kalium for Potassium and Natrium for Sodium. On the similar lines, several other elements are symbolized using the letters of their Latin names. The examples of such elements are mentioned below:

• Symbol of Iron is Fe which represents its Latin Name “Ferrum”
• Symbol of Gold is Au which represents its Latin Name “Aurum”
• Symbol of Silver is Ag which represents its Latin Name “Argentinum”
• Symbol of Copper is Cu which represents its Latin Name “Cuprum”
• Symbol of Tin is Sn which represents its Latin Name “Stannum”
• Symbol of Mercury is Hg which represents its Latin Name “Hydrargyrum”
• Symbol of Antimony is Sb which represents its Latin Name “Stibium”
• Symbol of Lead is Pb which represents its Latin Name “Plumbum”
• Symbol of Tungsten is W which represents its German Name “Wolfram”

First 20 Elements FAQs

What is the atomic number of hydrogen?

The atomic number of hydrogen is 1.

What is the valency of K, Ne, Ar and N?

The valency of an element is the number of electrons it can gain, lose, or share to achieve a stable electron configuration. Potassium (K) has a valency of 1, Neon (Ne) has a valency of 0, Argon (Ar) has a valency of 0, and Nitrogen (N) has a valency of 3.

Which element has the smallest mass?

The element with the smallest mass is hydrogen. It has an atomic mass of approximately 1.

What is special about the first twenty elements?

The first twenty elements, often referred to as the “first two periods” in the periodic table, hold significance as they represent the building blocks of matter. They include elements from hydrogen to calcium and showcase trends in properties such as atomic size, electronegativity, and reactivity.

Which element has the symbol He and is a noble gas?

Helium (He) is the element with the symbol He, and it is a noble gas.

Which element is commonly used in water purification and has the symbol Cl?

The element commonly used in water purification with the symbol Cl is chlorine.

What is the atomic mass of oxygen?

The atomic mass of oxygen is approximately 16.