Elements vs Compounds
Atoms are the tiny units, which collect up to form all the existing chemical substances. Atoms can join with other atoms in various ways, thus form thousands of molecules and other compounds. According to their electron donating or withdrawing abilities, they can form covalent bonds or ionic bonds. Sometimes there are very weak attractions between atoms. A chemistry student should have an idea about “element” and “compound”, and differentiate these two basic concepts.
What is an Element?
We are familiar with the word “element,” because we learn about them in the periodic table. There are about 118 elements given in the periodic table according to their atomic number. An element is a chemical substance, which consists of only single type of atoms; hence, they are pure. For example, the smallest element is the hydrogen and silver, gold, platinum are some of the commonly known precious elements. Each element has an atomic mass, atomic number, symbol, electronic configuration, etc. Although most of the elements are naturally occurring, there are some of the synthetic elements like Californium, Americium, Einsteinium, and Mendelevium. All the elements can be broadly categorized into three categories as metal, metalloids and non-metals. Further, they are categorized into groups and periods based on more specific characteristics. Elements in the same group or periods share certain common characteristics, and some properties may change sequentially when you go through a group or period. Elements can be subjected to chemical changes to form various compounds; however, elements cannot be further broken down by simple chemical methods. There are atoms of the same element with different number of neutrons; these are known as isotopes of an element.
What is a Compound?
Compounds are a chemical substance made up by two or more different chemical elements. Combinations of two or more of the same chemical elements are not considered as compounds but known as molecules. For example, diatomic molecules like O2, H2, N2 or polyatomic molecules like P4 are not considered as compounds, but they are considered as molecules. NaCl, H2O, HNO3, and C6H12O6 are some examples of common compounds. Therefore, compounds are a subset of molecules. The elements in a compound are joined together by covalent bonds, ionic bonds, metallic bonds, etc. The structure of the compound gives the number of atoms in the compound and their ratios. In a compound, elements are present in a definite proportion. We can find these details easily by looking at a chemical formula of a compound. Compounds are stable, and they have a characteristic shape, color, properties, etc.
What is the difference between Elements and Compounds?
• Elements are pure substances, which consist of only a single type of atom. In a compound, two or more elements are chemically bound together.
• In a compound, elements are present in defined ratio.
• The properties of an element often change completely when they are part of a compound.
• There are strong covalent bonds between atoms of the compound, but in elements, there can be metal bonds, or weak non-covalent forces.