1. Justify its position in the periodic table based on the electronic configuration of hydrogen.
 |
Hydrogen shows similarities with both alkaline metals and halogen, depending on their properties. Although some of its properties are completely different from those of alkaline metals and halogens. Based on these properties, let's consider the location of hydrogen in the periodic table.
Answer Hydrogen is the first element in the periodic table. its
The electronic configuration is 1s'. Like alkali metals, it can give up H + ion by discarding one electron. Like halogens, it can also form an H-ion by taking an electron. Like alkaline metals, it forms oxides, halides, and sulfides, although unlike ionic metals, its ionisation enthalpy is high and does not exhibit metallic behavior under normal conditions. In fact, in terms of ionisation enthalpy, it exhibits more similarity to halogens. Similar to halogens, it forms diatomic molecules, reacting with elements to form hydrides and many covalent compounds. Although unlike halogens, it has very little activity. Therefore, on the basis of the above properties, in the periodic table, hydrogen should be kept in class-1 with alkali metals and class-17 with first period or halogen and first period. Although similar in properties with alkali metals and halogens, it also shows differences in properties with alkali metals and halogens. Therefore, it should be given a separate space in the periodic table.
Physical Properties Physical Properties The physical properties of water are as follows
(i) Water is colorless, odorless and tasteless at room temperature.
(ii) It is transparent. It appears colorless in thin (thin) layers.
Is, but in thick layers (eg sea or deep lake) it Green-blue appears.
(iii) The concentration of water due to the concentration of H ′ and OH ions. Nature is indifferent, hence it can be found in litmus and other indicators. Does not react with.
(iv) Water molecules are polar and compact, due to whichThe value of the dielectric is high (80).
(v) Water due to high dielectric constant (dielectric)
Is solvent It forms bonds with polar molecules (molecules containing highly electronegative elements, F, O and N at the boundary space), which also dissolve covalent compounds such as alcohols, amines, carbohydrates, etc. in water. Inner it Also called universal solvent.
(vi) Boiling point of water is high due to hydrogen bonding. water Boiling point of 373 K (100 ° C) and melting point of 273 K (0 ° C) it happens. (vii) After reducing the temperature, the volume of water first decreases to 4 ° C. And then starts increasing, so the density of water is 277 K (4 ° C) But is the maximum (ie 1 g / cm). (viii) Relative heat, thermal conductivity and surface tension values of water
Are higher than other liquids. (iv) It is the conductor of electricity, its specific heat is 1. (x) To convert water from solid state to liquid state 80 calories of heat is required per gram. This of heat
The quantity is called the latent heat of ice.
(xi) To convert water from liquid state to vapor state 536 calories of heat are required per gram. This heat The secret heat of evaporation is called.
(xii) There is a very small amount of automatic ionization of water. Water at 25 ° C Has an ionic product of K., = 1.0x10-14, which in temperature Increase .. increases when it is.
(xiii) The dipole moment of a water molecule is 1.85 diopters.
