Read the following and answer any four questions from 18.1 to 18.5 Dmitri Mendeleev, father of periodic table developed a Periodic Table on the basis of atomic mass. He started with 63 elements, studied their chemical reactivity and arranged them in the order of increasing atomic masses. For his works in creating the first ever comprehensive periodic table, he was honoured as “Father of Periodic Table” 18.1 The general formula of oxide of elements present in the group IV of Mendeleev Periodic table is (a) RO2 (b) RO3 (c) RO4 (d) RO 18.2 Which of the following pair of elements was not placed according to Mendeleev’s Periodic Law by Mendeleev in his periodic table? (a) Co and Ni (b) Li and Be (c) N and O (d) Fe and Co 18.3 Mendeleev could not assign a fix position to hydrogen because (a) Hydrogen does not react with any other element (b) Hydrogen has completely filled shell (c) Hydrogen resemble alkali metals as well as halogens in properties (d) Hydrogen is highly reactive element 18.4 The formula of oxide of Eka-Aluminium is (a) Al2O3 (b) GeO2 (c) Sc2O3 (d) Ga2O3 5 / P a g e 18.5 The two elements selected by Mendeleev as the basis for the chemical reactivity are (a) Hydrogen and Nitrogen (b) Oxygen and Hydrogen (c) Hydrogen and Carbon (d) Oxygen and Nitrogen
Answers
Answer:
অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং টঃভথঃভথজঁলৈজলৈজণদছণৈথছেথঢেছথেচঢথেচঢেঢতচৃথেছণথণছেএথছঃদৈছৈলৈজশঁজদঁজদেঢ অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং টঃভথঃভথজঁলৈজলৈজণদছণৈথছেথঢেছথেচঢথেচঢেঢতচৃথেছণথণছেএথছঃদৈছৈলৈজশঁজদঁজদেঢ অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং টঃভথঃভথজঁলৈজলৈজণদছণৈথছেথঢেছথেচঢথেচঢেঢতচৃথেছণথণছেএথছঃদৈছৈলৈজশঁজদঁজদেঢ অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং অঁখকেঘজৌঈঔএখোগিগৈঔজূঈঊগীঔজীঔঈগূঈগৃঋকঘংচজংঈগংঐগংকঘংগীঅংগীনঁঋটৃপংপফং টঃভথঃভথজঁলৈজলৈজণদছণৈথছেথঢেছথেচঢথেচঢেঢতচৃথেছণথণছেএথছঃদৈছৈলৈজশঁজদঁজদেঢ সং