Gujarat Board Class 9 Science — Flashcards for Quick Revision

A: Matter is anything that occupies space and has mass. The two key properties are: (1) Mass - the amount of substance in an object, measured in kilograms (kg), and (2) Volume - the amount of space occup

A: This observation demonstrates that matter is made up of tiny particles. The salt particles spread throughout the water by fitting into the spaces between water particles. This proves that matter is no

A: This demonstrates that particles of matter are incredibly tiny - far beyond our imagination! A single crystal contains millions upon millions of particles. When diluted repeatedly, the particles keep

A: A pure substance is a form of matter in which all constituent particles are the same in their chemical nature. It consists of a single type of particle with uniform composition and properties througho

A: A mixture is matter composed of two or more pure substances (elements or compounds) that are physically combined without forming new chemical compounds. Examples: (1) Milk - mixture of water, fat, pro

A: Homogeneous mixtures have uniform composition throughout with no visible separate components. Example: Sugar dissolved in water appears the same everywhere. Heterogeneous mixtures show visible distinc

A: The Law of Conservation of Mass states that mass can neither be created nor destroyed during a chemical reaction. The total mass of reactants equals the total mass of products. Example: When 5.3 g sod

A: The Law of Conservation of Mass is important because it shows that atoms are not lost or created during chemical reactions—they are only rearranged. This principle helps scientists: (1) Balance chemic

A: The Law of Constant Proportions (also called Law of Definite Proportions) states that in a pure chemical compound, the elements are always present in the same proportion by mass, regardless of the sou