Matter and its Properties || Properties of Matter || CSS/PCS/PMS/IAS

Matter and its Properties || Properties of Matter || CSS/PCS/PMS/IAS

Matter and its Properties || Properties of Matter || CSS/PCS/PMS/IAS

Matter and its Properties:

Matter consists of atoms and molecules. Countless substances found in nature - needles, people, mountains, stars, everything we can think of - are made of atoms. Atoms combine to form molecules. For example, two hydrogen atoms combine with one oxygen atom to form a water molecule. A molecule can be as simple as a hydrogen molecule that consists of two hydrogen atoms, or as complex as a DNA (deoxyribonucleic acid) molecule that consists of millions of hydrogen, carbon, nitrogen, oxygen and phosphorus atoms. By definition, a molecule is the smallest molecule in a substance that has all of its chemical and physical properties. The molecule can be divided into atoms that have their own chemical properties.

States of Matter:

Matter usually exists in three states: solid, liquid and gaseous. In all states, the particles are constantly moving. In the body, the particles vibrate around fixed positions. The particles in the liquid also vibrate, but at the same time they move freely throughout the material. In gas, the molecules are much further apart than in solids and fluids and moving at high speeds. All substances can be transformed from one state to another by changing the temperature. Ice, water and steam are different states of the same substance. n There is a fourth state of matter - an ionized state called plasma. Although this condition is less common on earth, the sun and other stars are in this state.

Molecular Properties of Matter:

(i) Diffusion: 

Diffusion is the mixing of different gas molecules, liquids and even solids. When the perfume bottle opens in one corner peace, its particles mix with the particles of air, and the smell spreads soon to the far corner of the room. Diffusion in liquids is not as fast as in gases. Sugar crystals placed on the bottom of the bottle containing water will dissolve in water to get a homogeneous solution in a few weeks. Diffusion also occurs in solids, albeit at a very low speed.

(ii) Surface Tension: 

Pond skater can move easily on the surface of the water.A slight depression of the surface is created by the legs of the insect, which shows that the surface acts as a flexible "skin". If the needle is placed on a small piece of paper, which is then placed on the surface of the water, the paper sinks in a few seconds, leaving the needle floating in the water. A thorough examination reveals that the needle rests in a light cavity, as if it were lying on elastic skin. Thus, the surface of the liquid behaves like a flexible membrane and therefore tends to shrink. This behivour of a liquid is called surface tension. Surface tension is due to molecular attraction.

After dipping the brush in water, all hair is spread out, but when removed, it is covered with a thin layer of water, which shrinks due to surface tension and draws hair to itself. Liquid droplets, such as rain drops, water drops, molten metal drops, dew drops, etc. are spherical because their surface shrinks to give a minimal surface. The ball has a minimum surface for a given volume. Soaps and detergents less the surface tension of H2O(water). This increases the wetting strength of the water or its ability to remove dirt particles from clothes and dishes. Mosquitoes breed in stagnant water. Their larvae float on water due to surface tension. When oil is sprayed with stagnant water, its surface tension decreases, causing larvae to drown and die.

(iii) Capillarity: 

If a clean glass tube with a small inside diameter (called a capillary tube) is immersed in water, the water will rise in the tube. This phenomenon is called capillary action. Water floats in the capillary tube because the water molecules attract more to the glass than to each other. If the same capillary tube is immersed in mercury, the level of mercury in the tube is lower than the level outside, because mercury particles are less attracted to the glass than to each other. The attraction force between different molecules is called adhesion and cohesion between similar molecules. The molten candle wax is drawn into the wick by capillary action. For the same reason, oil raises the leopard.

If one end of the sugar cube is immersed in tea, the whole cube will get wet quickly due to capillary action. The fine pores of the paper act as small capillary tubes. The ink is rising into the paper through these seasons. The capillary action in soil is important in bringing water to the roots plants The bricks are porous and therefore ground water can seep through the capillaries share. To avoid moisture in the building, a layer of non-porous material, such as a slate it is necessary in its foundation. A drop of water spreads on the glass plate because of the water adhesion glass particles are larger than their integrity. A drop of mercury remains almost spherical, because the coherence of mercury particles is greater than their adhesion to glass.

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