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Why do the transition elements have higher boiling & melting points ?

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Because of having larger number of unpaired electrons in their atoms, they have stronger interatomic interaction and hence stronger bonding between atoms. Hence strong metallic bonds between the atoms of these elements attribute to their high melting point and boiling point.


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KEY CONCEPTS FOR TRANSPORTATION IN HUMANS (NEET/11th)

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  BLOOD ➖The blood is responsible to transport food, oxygen, and waste materials in human bodies. ➖Blood usually consists of a fluid medium known as plasma where the cells remain suspended. ➖Plasma is responsible to transport food, carbon dioxide, and nitrogenous wastes in dissolved form. ➖However, oxygen is carried by the red blood cells. ➖Many other substances such as salts, are also transported by the blood. A HUMAN HEART ➖The heart is one of the most significant muscular organs of a human body. ➖As both the oxygen and the carbon dioxide get transported by the blood; so, to avoid the oxygen-rich blood from mixing with the blood containing carbon dioxide, the heart has different chambers. ➖Oxygen-rich blood from the lungs comes to the thin-walled upper chamber of the heart on the left, i.e. the left atrium (see the image given above). ➖When it is collecting the blood, the left atrium relaxes; however, while the next chamber, i.e. the left ventricle expands, then it (l...
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KEY CONCEPTS FOR GENETIC TERMINOLOGY (BIO - NEET/11th/12th)

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▪️ Allele➖An alternative form of a gene ▪️ morph➖A silent gene ▪️ Angelman syndrome➖a rare genetically inherited form of mental retardation ▪️ Autosome➖Synonymous with somatic chromosomes ▪️ Chimera➖An exceptionally rare person composed of the cells derived from different zygotes ▪️ Chromosome➖Rod-shaped or thread-like structures located within the cell nucleus that carry genes encoded by DNA ▪️ Cloned gene➖A recombinant DNA molecule along with the gene of interest ▪️ Consanguinity➖Having a common ancestor, i.e., blood relations ▪️ Crossing over➖The exchange of genetic material between a pair of homologous chromosomes ▪️ Cross-pollination➖Mating of two genetically different plants (but of the same species). ▪️ Dizygotic twins➖Twins produced from two separate ova, which are separately fertilized ▪️ Deoxyribonucleic acid (DNA)➖Composed of nucleic acids, DNA encodes the genes that facilitate genetic information to be passed to offspring. ▪️ Evolution➖Genetic change in a popula...
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FULL NOTES FOR THERMAL PROPERTIES OF MATTER

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NOTES ON THERMAL PROPERTIES OF MATTER Heat:- Heat is the agent which produces in us the sensation of warmth and makes bodies hot. It is form of energy. The part of thermal energy which flows from one body to the other due to temperature difference is called heat. Nature of heat:- (a) The weight of a body remains the same weather it is heated or cooled. (b) Heat flows from higher to lower temperature (c) In any exchange of heat, heat lost by the hot body is equal to the heat gained by the cold body. (d) Substances generally expand when heated (e) A certain amount of heat known as latent heat is required to change the state of a body from solid to liquid or from liquid to gas without any change in temperature. Thermal Energy:- In accordance to dynamical theory of heat the sum total of translational, vibrational and rotational energies of the molecules of a system is called the thermal energy of the system . Unit of Heat:- (a) Calorie (cal):- It is the amount of heat required ...
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An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase? ( neet pyq )

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Question: An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase? 1. Addition of NaCl 2. Addition of Na2SO4 3. Addition of 1.00 molal KI 4. Addition of water Answer:  An aqueous solution is molal in . So, the addition of water will cause the vapour pressure to increase. This is according to Raoult's Law. In the other three options, electrolyte undergo ionization, which leads to lowering of vapour pressure. Hence, the correct option is D Or  According to raoults law Ps = PoXa (Xa = mole fraction of solvent) and on addition of water the mole fraction of water in the solution increases therefore vapour pressure increases.
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