KERALA PSC / CHEMISTRY / GENERAL CHARACTERISTICS OF THREE PHYSICAL STATES OF MATTER / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

 

KERALA PSC / CHEMISTRY / GENERAL CHARACTERISTICS OF THREE PHYSICAL STATES OF MATTER / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / GENERAL CHARACTERISTICS OF THREE PHYSICAL STATES OF MATTER / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

Solid State

·      Solids are rigid and have definite volume and shape.

·      Intermolecular force of attraction is very strong in solids

·      In solids, the constituent particles (atoms, ions or molecules) are completely fixed to their own position.

·      In solids, kinetic energy of the particles is very small

·      Solids are almost incompressible

·      Solids are diffuse very slowly compared to liquids and gases

·      Solids can be classified into 2 categories: Crystalline solids and amorphous solids

·      All elements and compounds (including alloys) are crystalline solids. Rubber, glass, plastics are amorphous solids

·      Unit cells are 3 – dimensional group of lattice points that generate the whole lattice

·      Three types of unit cells are simple, face centered and body centered

·      There are 7 Crystal systems: Cubic, Monclinic, Triclinic, Tetragonal, Orthorhombic, Trigonal & Henagonal

·      Space Lattice: It is a regular repeating arrangements of points in space and forms the basis of classification of all structures.

 

Liquid State

·      Liquids have no definite shape but have definite volume

·      Liquids are less compressible than gases, but more compressible than solids

·      In a liquid, the particles are neither completely ordered nor completely disordered

·      Liquids diffuse faster than solids but much slower than gases

·      Kinetic energy of particles in the liquid state will be higher than that in the solid state.

 

Gaseous State

·      Gases have neither definite volume nor definite shape. They take the shape and volume of the container

·      In gases, the particles are far apart from one another

·      The intermolecular forces of attraction are very weak

·      Gases are highly compressible

·      Gaseous state is the least ordered state

·      Change of temperature and pressure causes considerable change in volume

·      Gas molecules possess very high kinetic energy

 

 

·      The state in which matter exists depends upon temperature and pressure

·      For example, water is in the liquid state at room temperature and atmospheric pressure

·      At 0ºC and atmospheric pressure, it exists as a solid (ice)

·      When heated to 100ºC at atmospheric pressure, water is converted into a gas (steam)

·      The fourth state of matter is plasma and the fifth state is liquid crystal. The two of the three states of matter can coexist in the same substance.

·      Matter undergoes changes which may be either chemical or physical change

·      A physical change alters only the physical properties of matter and it is temporary

·      A chemical change alters the chemical properties of substances and it is permanent. Matter exist in nature as pure substances and mixtures.

·      Pure substances have some composition and properties

·      Pure substances are divided into element and compounds

·      An element is the simplest form of matter and it cannot be decomposed by ordinary chemical reaction. Eg: oxygen, calcium, sodium, hydrogen etc…

·      An element consists of only one kind of atoms

·      A compound is a substance made up of elements chemically combined in a fixed proportion by weight. Eg: oxygen and hydrogen combine to form water which is compound

·      Elements in a compound lose their individual chemical characteristics

·      A material obtained by mixing two or more substances in any proportion is known as mixtures. Eg: Mixture of sand and sugar

·      In a mixture, the components do not lose their identity

·      The components of a mixture can be easily separated by ordinary methods

·      Mixtures are of two types: Homogeneous mixture and heterogeneous mixtures

·      Homogeneous mixtures have the same composition throughout the sample. Eg: Salt solution, sugar solution etc…

·      Heterogeneous mixtures have different compositions and the components are distinguishable. Eg: Carbon and Sulphar Mixture (Gun Powder)

·      Super Fluidity: Fluidity is the property of liquid, lesser the viscocity more is the fluidity certain liquid have almost no viscocity therefore such liquid can act as superfluid, no effective resistance to their flow, such super fluid when kept in a container it would goes up and flow out the vessel. Eg: Helium on cooling to 2.178 K it became a super fluid.

·      Super Conductivity: A substance is said to be super conductor when it offer no resistance to flow of electricity. There is no substance which is super conducting at room temperature. Some substance show super conductivity at very low temperature, it was discovered by Kammerlingh Onnes in 1919. Eg: Mercury – shows super conductivity at temperature 4 K.

KERALA PSC / CHEMISTRY / GENERAL CHARACTERISTICS OF THREE PHYSICAL STATES OF MATTER / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY