What Are Chemical Elements? Definitions, Properties & Examples
An element of chemistry is defined as a pure substance composed of atoms where all atoms in their nuclei have the same numbers of protons. Chemical elements cannot be broken down by any reactions into simpler substances. The defining property of elements is the number of protons in their nuclei and it is referred to as an atomic number of elements. Atoms are rearranged into new compounds held together by chemical bonding when different elements undergo chemical reactions. Most of the elements are found as compounds or mixtures, only a few elements, such as silver and gold, are found uncombined as relatively pure native element minerals.
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History of Elements
The elements have been used for different purposes since ancient times. It is estimated that around 1000 years ago, gold (Au) was used for making ornaments during the period of the stone age. In Egypt, different types of metals such as silver (Ag), iron (Fe), lead (Pb), copper (Cu) and tin (Sn) were used for different objectives more than 5,000 years ago. The discovery of arsenic (As) has happened around A.D. 1250. Around twelve elements were known by 1700.
The concept of elements or we can say the theory that there are a limited number of fundamental pure substances out of which all other substances are made is credited to the ancient Greeks. There are four basic "roots" of all materials: earth, air, fire, and water was proposed by Empedocles (c. 495–435 B.C.). The famous philosopher Plato termed these four roots as stoicheia elements.
Examples of Elements
Some examples of elements are given below.
Examples of Elements in Everyday Life
We use elements in everyday life. We are dependent on these elements for our survival. The most important examples of elements in everyday life are carbon, hydrogen, oxygen and apart from these chlorine, sulphur, calcium, iron, phosphorus, nitrogen, sodium, and potassium are also essential for everyday life. The four major elements that are used in the making of 96% of the human body are carbon (C), oxygen (O), hydrogen (H) and nitrogen (N). In the body of a human being, a large number of chemical reactions occur involving compounds of all of these elements as a result of these reactions the human body used to function.
Examples of Elements Compounds and Mixtures
The physically combined structures which can be separated back into their original components are known as mixtures. It is very rare to find pure samples of isolated elements in nature. In mineral samples from the crust of the earth most of the naturally occurring elements have all been identified, only a small minority of them can be found as recognizable, relatively pure minerals. Among the more common such native elements are copper, silver, gold, and sulphur. Carbon is an element that occurs naturally in diamonds, coal and graphite. The noble gases, for example neon and noble metals, for example mercury can also be found in their pure, non-bonded forms in nature.
When the chemical bonds are formed between the atoms of two distinct elements that are chemically combined the result is called a chemical compound. Most of the chemical elements present on the earth make bonds with each other in order to form chemical compounds, for example when sodium ions and chloride ions combine they form NaCl. Another example of a chemical compound is water (H2O).
Examples of Elements in Chemistry
The chemical elements are classified and placed in different groups in the periodic table. The table of chemical elements is the representation of the chemical elements in tabular form. There are a total of 118 elements placed at present in the periodic table among them 94 are natural elements and 24 elements are synthetic. The elements are placed in groups in the periodic table; the names of these groups are alkali metal, alkaline earth metal, pnictogen, chalcogen, halogen, and noble gases. The groups of the periodic table are referred to by their number. The list of elements placed in the periodic table is very long but some important examples of elements in chemistry are hydrogen, oxygen, iron, copper, potassium, calcium, helium, nitrogen, silver etc.
Examples of Elements Found at Home
Elements are also used at home for a variety of purposes. In Incandescent light bulbs, argon and tungsten are used. Copper is an important element that is found in every home in the form of electric wiring or utensils. Mercury element is used in some thermostats and in switches. Gold and silver elements are used for jewellery purposes.
Do you Know?
The elements which are found on mars are exactly the same as the elements of the earth.
In ancient times the elements were referred to as fire, earth, water, and air.
Conclusion
An element of chemistry is a pure substance that is composed of similar types of atoms. Atoms of an element have an atomic number, which indicates the total number of protons present in the nucleus of a single atom of that element. We get all the necessary information related to elements and examples of elements compounds and mixtures, at home, in chemistry etc.
FAQs on Elements in Chemistry: Complete Guide for Students
1. What is an element in chemistry?
An element is a pure substance that consists of only one type of atom, distinguished by its unique number of protons. This number is known as the atomic number (Z). Elements are the fundamental building blocks of all matter and cannot be broken down into simpler substances by any chemical means. For example, a pure sample of iron (Fe) contains only iron atoms.
2. What are some common examples of elements and their symbols?
Elements are represented by unique one or two-letter symbols. Here are ten common examples:
- Hydrogen (H)
- Helium (He)
- Carbon (C)
- Nitrogen (N)
- Oxygen (O)
- Sodium (Na)
- Aluminium (Al)
- Chlorine (Cl)
- Iron (Fe)
- Gold (Au)
3. How are elements classified based on their properties?
Elements are broadly classified into three main categories based on their physical and chemical properties:
- Metals: These are typically shiny, malleable, ductile, and good conductors of heat and electricity. Examples include Iron (Fe), Copper (Cu), and Gold (Au).
- Non-metals: These are generally poor conductors, not shiny, and brittle in their solid state. Examples include Oxygen (O), Carbon (C), and Sulphur (S).
- Metalloids: These elements exhibit properties intermediate between metals and non-metals. They are also known as semi-metals. Examples include Silicon (Si) and Germanium (Ge).
4. What is the importance of elements in the human body?
Elements are essential for the growth, maintenance, and functioning of the human body. The four most abundant elements—Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N)—make up about 96% of the body's mass. Other crucial elements include Calcium (Ca) for bones, Iron (Fe) for haemoglobin in the blood, and Sodium (Na) and Potassium (K) for nerve function.
5. How is an element different from a compound and a mixture?
The key difference lies in their composition and bonding. An element is a pure substance made of only one type of atom (e.g., Oxygen, O). A compound is a pure substance formed when two or more different elements are chemically bonded in a fixed ratio (e.g., Water, H₂O). A mixture consists of two or more substances that are physically mixed but not chemically bonded, and their proportions can vary (e.g., salt dissolved in water).
6. Why is the atomic number considered the fundamental identity of an element, not the mass number?
The atomic number (Z) represents the number of protons in an atom's nucleus. This number is unique to each element and determines its chemical properties. The mass number (A) is the sum of protons and neutrons. While the number of neutrons can vary (creating isotopes), the number of protons for a given element is always constant. Therefore, the atomic number is the definitive identifier of an element.
7. How can atoms of the same element, like Carbon, have different masses (e.g., Carbon-12 and Carbon-14)?
Atoms of the same element that have different masses are called isotopes. This variation occurs because they have the same number of protons but a different number of neutrons in their nucleus. For example, both Carbon-12 and Carbon-14 have 6 protons (which makes them Carbon), but Carbon-12 has 6 neutrons while Carbon-14 has 8 neutrons. This difference in neutron count results in a different mass number.
8. Why are noble gases like Helium (He) and Neon (Ne) considered elements if they are so unreactive?
An element is defined by its atomic structure (number of protons), not by its reactivity. Noble gases are elements because they are made of atoms with a unique atomic number—Helium has 2 protons and Neon has 10. Their lack of reactivity is a chemical property that results from having a full outer shell of electrons, which makes them very stable. Their elemental identity, however, is unquestionable.
9. Why have scientists not yet officially discovered Element 119?
Creating new, superheavy elements like Element 119 is extremely challenging due to nuclear instability. As the atomic number increases, the electrostatic repulsion between the large number of protons in the nucleus becomes immense. Scientists attempt to create such elements by bombarding a target element with ions in a particle accelerator, but the resulting nucleus is often incredibly unstable and decays in a fraction of a second, making detection and verification exceptionally difficult.
