Category: science

(i) ZnS have large difference in the size of their ions and due to this it shows Frankel defect. (ii) AgBr shows Schottky defect and Frankel defect.

In a square close packed two dimensional layer , four other particles touch one particle. Thus its coordination number is 4 .

On heating the crystal lattice, some of the lattice particles gain enough energy that they jump from their lattice points. Due this the crystal appears coloured and its density decreases.

These are the points in a crystal lattice that can be occupied by an atom, ion or a molecule.

In case of solids the particles have strong forces of attractions between them . Due to this they can not move or change their positions. Due to this they are rigid.

It is the foul smell produced by the oxidation of oils and nuts. Mostly the bitter taste of peanut and food made by frying is due to rancidity . Normally the oily substances which are not covered properly , react with the oxygen of air and get oxidised thus give a foul smell. Removal of

Magnesium is a reactive metal, it reacts with the oxygen of air and forms magnesium oxide. Magnesium oxide makes a layer on the upper surface of the metal. Which makes it difficult for the magnesium to get burnt and give characteristic flame. By using sandpaper we can remove its upper layer for proper combustion reaction

  Molecular solids Covalent solids Metallic solids Ionic solids 1 These are made up of molecules. These are formed by the network formed by the atoms. These solids are formed in metals only by the special bonding. These are formed by the electrostatic attraction between oppositely charged ions. 2 The molecules are held by the

It is the substance that increases the rate of reaction and itself is recovered in the same amount at the ending of reaction. It lowers the activation energy by providing an alternative pathway. And makes the reactants to cross the energy barrier easily. Mostly the transition metals like Iron, Cobalt ,Nickel , Platinum etc are

In case of PCl5 the bond pairs present on the axial position suffer more repulsion than that of bond pairs present on the equatorial position. Actually each bond pair present at the axial position has to face the repulsion of three equatorial bond pairs, due to this the bond is stretched and hence the bond

In case of hydrogen iodide the bond length is larger as compared to hydrogen fluoride. As the size of fluorine is smaller than iodine, the bond between hydrogen and fluorine is stronger and have lower bond length. This makes it harder to break the bond and release H+ ions. But in case of Hydrogen iodide

1. Zinc blende – ZnS 2. Calamine – ZnCO3 Uses of Zinc metal. The zinc metal is used for the manufacture of dying or painting , also for galvanization of iron. It is also used as the outer cover of dry cell and as a cathode also. Ores of copper and their uses Copper pyrites

Void is the empty space present in the crystal lattice. It is the unoccupied space in between the lattice points. There are:- 1. Tetrahedral void 2. Octahedral void

Step 1 : Assume the percentage as grams and divide it with molar mass. Step 2: By this way you have calculated the number of moles , further divide evey term with the smallest term which you have calculated in step 1. Step 3 : Now you have the simple whole number ratio of elements