3) A of a compound is formed by a chemical combination of atoms of two or more elements.
Answers
Answer:
Elements are the simplest form of matter whereas molecules are the simplest form of matter which can have an independent existence. Molecules can contain any number of atoms. Atoms have the same number of protons and electrons. So, it is a neutral particle. Matter consists of mixtures and also pure substances. Mixtures can be separated into their components by physical means whereas pure substances cannot be separated into their components by any physical means. If the pure substance is an elemental substance, then it is an element. If the pure substance is a compound substance, then it is a compound. Examples include water H2OH2O and table salt NaClNaCl.
Therefore, a combination of two or more elements chemically combined is called a compound.
Note: A molecule can have two or more atoms of the same element or different elements. A compound consists of atoms of two or more different elements. The properties of resultant compounds are different from those of the properties of elements from which they are formed. Compounds can be broken down into simpler substances by chemical means but cannot be broken by physical means. In a compound, the ratio of component atoms remains the same. Therefore, a combination of two or more elements chemically combined is a compound.