This page is part of Matter in our Surroundings Class 9 notes for Chemistry.Topics covered in this page are
These two factors decide whether a given substance would be in a solid, liquid or gaseous state.
Test your Knowlegde
Fill in the blanks
(1) The process in which a solid substance converts into a liquid on heating,is called ___________
(2) The temperature at which a solid substance melts and changes into a liq uid at atmospheric pressure,is called __________________.
(3)Higher the melting point of a solid substance, greater will be the __________________ of attraction between its particles.
(4)At the melting point, the particles of a solid have sufficient kinetic __________________ to overcome the strong forces of attraction holding them in fixed positions and break to form small groups of particles and the solid melts to form aliquid.
(5) The process in which a liquid substance change into a gas rapidly on heating, is called _________
(6) The process of changing a __________________ to a liquid by cooling is called condensation.
(7) The process of changing a __________________ into a solid by cooling is called freezing.
(8) The changing of a solid directly into vapours on heating and of vapours into solid on cooling, is known as __________________.
(9) The three common substances which undergo sublimation are: ______,______ and _______
(10) In Sublimatio,when the solids are heated, their particles move so quickly that they separate completely to form __________________ .
(1) melting or fusion.
(2)Melting point of subsstance
(9) Iodine,Camphor ,Naphthalene