What Are Elements? Definitions, Properties & Practical Examples
An element is a pure substance composed of only one type of atom. The smallest piece of an element is the single atom. The chemical elements combine together to produce new substances. All the matter you see around yourself is composed of these elements. For example Iron, Aluminum, oxygen, gold, silver, and hydrogen.
Elements are the building blocks for all other matter in the universe. Iron, oxygen, hydrogen, gold, and helium are examples of elements.
Even though all elements are composed of the same atoms, they can take various forms. They can be solid, liquid, or gas depending on their temperature. They can also take various shapes depending on how closely the atoms are packed together. Scientists refer to these as allotropes.
For example- Carbon is one such example. Carbon atoms can form diamond, coal, or graphite depending on how they fit together.
Elements in the Periodic Table
Essential Element Facts:
The same elements can be found all over the universe. The elements found on Mars and in the Andromeda Galaxy are the same as those on Earth.
There are various forms of pure elements known as allotropes. Diamond, graphite, buckminsterfullerene, and amorphous carbon are examples of carbon allotropes. Even though they are all made up of carbon atoms, these allotropes have distinct properties.
The periodic table arranges elements in increasing atomic number (number of protons) order. The periodic table arranges elements according to periodic properties or recurring trends in the properties of the elements.
Mercury and bromine are the only two liquid elements at room temperature and pressure.
The periodic table contains 118 elements, but only 114 of these elements had been confirmed to exist. There are still new elements to be discovered.
Many elements are found in nature, but some are artificial. Technetium was the first element created by humans.
Metals account for more than three-quarters of all known elements. Metalloids and semimetals are nonmetals and elements with properties that fall between metals and nonmetals.
Hydrogen is the most significant element in the universe. Helium is the second most abundant element.
Ancient man was exposed to several pure elements found in nature, such as carbon, gold, and copper, but these substances were not recognized as elements. The first elements were considered Earth, air, fire, and water – substances that we now know are made up of multiple elements.
Periodic Table
Arrangement of Elements in the Periodic Table:
Mendeleev's periodic table is similar to the modern periodic table, but Mendeleev's table ordered elements by increasing atomic weight. The modern table arranges the elements in increasing atomic number order (which is not Mendeleev's fault because he did not know about protons at the time).
Like Mendeleev's table, the modern table groups elements based on common properties. The periodic table's columns are element groups. Among them are alkali metals, alkaline Earth, transition metals, basic metals, metalloids, halogens, and noble gases.
The two rows of elements located beneath the main body of the periodic table belong to a subset of transition metals known as rare earth elements. The bottom row contains the actinides.
Groups in Periodic Table
Groups
Group 1: Alkali metals group
The first group (group 1) on the periodic table is the group of alkali metals.
The elements that make up the group of alkali metals include;
Lithium (Li)
Sodium (Na)
Potassium (K)
Rubidium (Rb)
Cesium (Cs)
Francium (Fr)
Group 2: Alkaline earth metals group
Group 2 elements on the periodic table are alkaline earth metals.
The elements that make up the group of alkaline earth metals are;
Beryllium (Be)
Magnesium (Mg)
Calcium (Ca)
Strontium (Sr)
Barium (Ba)
Radium (Ra)
Group 3-12: Transition and Inner transition metals group
Transition metals and inner transition metals are terms used to describe the elements that are found in groups 3 through 12 of the periodic chart.
These groups also contain the two bottom rows of the periodic table's elements.
Due to the fact that they exhibit a few distinct characteristics, they are arranged in two separate rows at the bottom.
The items in the bottom rows are actually just group 3's extension. Therefore, they are a part of group 3.
These components are categorised as distinct elements known as inner transition elements since they have a limited number of unique characteristics.
Group 13: Boron group
The 13th group on the periodic table is the boron group.
The elements that make up the boron group include;
Boron (B)
Aluminium (Al)
Gallium (Ga)
Indium (In)
Thallium (Tl)
Nihonium (Nh)
Group 14: Carbon group
Group 14 on the periodic table is the carbon group.
The following substances belong to the carbon group:
Carbon (C)
Silicon (Si)
Germanium (Ge)
Tin (Sn)
Lead (Pb)
Flerovium (Fl)
Group 15: Nitrogen group
The periodic table's group 15 represents the nitrogen element.
The substances of the nitrogen group are;
Nitrogen (N)
Phosphorus (P)
Arsenic (As)
Antimony (Sb)
Bismuth (Bi)
Moscovium (Mc)
Group 16: Oxygen group
Group 16 on the periodic table is the oxygen group.
The substances in the oxygen group are;
Oxygen (O)
Sulphur (S)
Selenium (Se)
Tellurium (Te)
Polonium (Po)
Livermorium (Lv)
Group 17: Halogen group
Group 17 on the periodic table is the halogen group.
The substances of the halogen group are;
Fluorine (F)
Chlorine (Cl)
Bromine (Br)
Iodine (I)
Astatine (At)
Tennessine (Ts)
Group 18: Noble gases group
The group of noble gases is the last group on the periodic table (group 18).
The elements that make up the group of noble gases are;
Helium (He)
Neon (Ne)
Argon (Ar)
Krypton (Kr)
Xenon (Xe)
Radon (Rn)
Oganesson (Og)
Solved Questions:
1. How many elements are there?
118
100
80
108
Ans: A) 118
2. Elements made of atoms.
TRUE
FALSE
Ans: A) True
3. What is the first element?
Nitrogen
oxygen
Hydrogen
Carbon
Ans: C) Hydrogen
FAQs on Key Facts About Elements
1. What is an element, and what is its most basic unit?
An element is a pure substance that cannot be broken down into any simpler substances through chemical reactions. The most basic unit of an element is the atom. Every atom of a particular element, like iron (Fe) or oxygen (O), has the same number of protons in its nucleus.
2. How are elements identified and distinguished from one another?
Each element is identified by its unique atomic number. This number represents the count of protons within the nucleus of a single atom of that element. Since no two elements share the same number of protons, the atomic number serves as a unique identifier. For instance, hydrogen has an atomic number of 1, while helium has an atomic number of 2.
3. What is the main difference between an element and a compound? Provide a clear example.
The primary difference lies in their composition. An element is a fundamental substance made of only one type of atom (e.g., pure Oxygen, O). In contrast, a compound is a substance formed when two or more different elements are chemically bonded together in a fixed ratio. For example, water (H₂O) is a compound because it is formed by chemically combining two hydrogen atoms and one oxygen atom.
4. Is water considered an element? Explain why or why not.
No, water is not an element; it is a compound. This is because a molecule of water (H₂O) is composed of two different elements that are chemically joined: two hydrogen (H) atoms and one oxygen (O) atom. By definition, an element must consist of only one type of atom.
5. What are some interesting facts about the elements on the periodic table?
The periodic table reveals many fascinating facts about the building blocks of matter. Here are a few examples:
Hydrogen (H) is the lightest and most abundant element, making up about 75% of the mass of the entire universe.
The vast majority of known elements, such as iron, copper, and gold, are classified as metals.
The only letter in the English alphabet that does not appear in any element symbol or name on the periodic table is 'J'.
Astatine (At) holds the title of the rarest naturally occurring element on Earth.
6. Which is the most abundant element in the universe versus on Earth?
The most abundant element in the entire universe is Hydrogen (H), which serves as the primary fuel for stars like our Sun. However, on our planet, the most abundant element in the Earth's crust is Oxygen (O). It constitutes about 47% of the crust's mass and is found in rocks, soil, water, and the air we breathe.
7. How are elements represented using symbols, and why is this system used?
Elements are represented by a universal system of chemical symbols, which are typically one or two-letter abbreviations. This system is used for global consistency and to simplify writing complex chemical formulas. The rules are:
The first letter is always capitalized.
If a second letter is needed, it is always lowercase.
Common examples include C for Carbon, Cl for Chlorine, and Na for Sodium (from its Latin name, *Natrium*).
8. Why is the periodic table so important for studying elements?
The periodic table is essential because it is a systematic chart that organises all known elements based on their atomic structure and chemical properties. Its structure helps scientists and students to:
Predict an element’s behaviour based on its position.
Understand trends in properties like reactivity and size.
Quickly identify if an element is a metal, non-metal, or metalloid.
9. Can new elements still be created, and if so, how?
Yes, new elements can be created, but only in highly specialised laboratories. While all naturally occurring elements have been discovered, scientists can synthesize new, super-heavy elements. This is achieved using particle accelerators to smash the nuclei of lighter elements together at immense speeds. These new elements are typically highly radioactive and unstable, existing for only fractions of a second before decaying.
