ICSE Class 9 Chemistry Chapter 1: The Language of Chemistry

The Language of Chemistry

• Matter is anything that occupies space and has mass.
• Matter can exist in three states: solid, liquid, and gas.
• Physical properties of matter are characteristics that can be observed or measured without changing the identity of the substance.
• Chemical properties of matter are characteristics that describe the ability of a substance to undergo a specific chemical change.

Chemical Nomenclature

• Chemical nomenclature is the system of rules used to name chemical compounds.
• The IUPAC (International Union of Pure and Applied Chemistry) system is used to name chemical compounds.
• The IUPAC system provides a set of rules for naming compounds based on their structure and composition.

Symbols and Formulae

• Symbols are one- or two-letter abbreviations used to represent elements.
• Formulae are combinations of symbols used to represent compounds.
• The symbol of an element is derived from its Latin or Greek name.
• The atomic number of an element is represented by the symbol Z.

Chemical Equations

• Chemical equations are used to represent chemical reactions.
• A chemical equation is a symbolic representation of a chemical reaction.
• Chemical equations must be balanced, meaning that the number of atoms of each element is the same on both the reactant and product sides.
• Chemical equations are used to illustrate the reactants, products, and direction of a chemical reaction.

Chemical Formulae of Compounds

• Compounds are formed when two or more elements combine in a fixed ratio.
• The chemical formula of a compound is a representation of the composition of the compound.
• The chemical formula of a compound is written with the symbol of the element that is present in the largest amount first.
• The chemical formula of a compound provides information about the composition of the compound.