ICSE Class 9 Chemistry — Flashcards for Quick Revision

A: An element is a simple and pure form of matter which cannot be decomposed into simpler substances. Example: carbon, hydrogen, oxygen.

A: Symbols are short forms for elements. They represent the name of the element, one atom of the element, and the quantity of the element equal in mass to its atomic mass or gram atomic mass. Example: N

A: Co means the element cobalt. CO means the compound carbon monoxide. Capital letters matter in chemistry because changing case changes meaning completely.

A: A chemical reaction is the process of breaking the chemical bonds of the reacting substances and making new bonds to form new substances. It changes reactants into products.

A: A chemical bond is the force that holds the atoms of a molecule together, as in a compound. Bonds break in reactants and new bonds form in products.

A: General combination reaction: A + B → AB. Two substances combine to form a single new product.

A: Water is H2O. Chemical name: Dihydrogen oxide. Molecular mass: 18 amu.

A: Water has a high dielectric constant, so it reduces the attraction between positive and negative ions and dissolves many substances. It dissolves solids, gases, and some liquids, so it is called the u

A: Solute: the substance that dissolves. Solvent: the medium that dissolves the solute and forms the solution. Example: In salt solution, salt is the solute and water is the solvent.