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Chemistry comes alive-2
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CHEMISTRY COMES ALIVE
Matter : Matter is any substance that possesses a mass and occupies space so that it can be detected and
Matter occurs in three states (i) Solid (ii) liquid (iii) Gases.
Energy : It is the capacity to do work. Every physical and physiological activity requires energy hence
energy is essential for life.
Note : Matter and energy are closely related to each other. And universe is a “matter-energy complex”.
Forms of energy :
(a) Potential energy or stored energy : The energy which is present in the chemical bonds of the substance
or due to the position of the object is called potential energy.
(b) Kinetic energy : Energy due to the motion of the object is called kinetic energy.
FORMS OF KINETIC ENERGY
(i) Energy of heat
(ii) Radiant energy
(iii) Mechanical energy
(iv) Electrical energy
(v) Sound or sonorous energy
(vi) Atomic or nuclear energy
COMPOSITION OF MATTER
Matter is any substance that possesses mass and occupied space.
Physical organization of matter : Three grading levels occurs in the organization of matter.
(i) Sub atomic level : At this level matter contains three fundamental particulate units known as electrons,
(ii) Atomic level : Proton’s, neutrons and electron associated in increasing numbers and form second level
unit of matter known as “Atom”. Atom is smallest unit of matter that participates in chemical reaction
without dissociation. So atom known as the primary reactive unit of the matter.
(iii) Molecular level : Association of two or more atoms form molecules which is of two types.