atoms and molecules class-9

atoms and molecules class-9


HELLO FRIENDS ONCE AGAIN WELCOME TO MY CHANNEL LEARNING POINT THIS IS KARTIKEY GOEL AND I AM HERE WITH MY NEW VIDEO BASED ON ATOMS AND MOLECULES SO WITHOUT WASTING TIME, LETS GET STARTED!!! IN THE ANCIENT TIMES INDIAN AND GREEK GREEK PHILOSOPHERS HAVE ALWAYS WONDERED AND AND WERE CONFUSED ABOUT THE DIFFERENT FORMS OF MATTER AND HOW ALL THESE MATTERS THAT ARE EXISTED ARE FORMED AND VARIOUS PHILOSOPHERS CAME UP WITH DIFFERENT THEORIES ONE SUCH COMMON IDEA AT WHICH INDIAN AND GREEK PHILOSOPHERS ARRIVED WAS THE IDEA OF DIVISIBILITY. DIVISIBILITY. IT STATED THAT IF WE GO ON DIVIDING THE MATTER A STAGE WILL COME WHEN PARTICLES CANNOT BE DIVIDED FURTHER THE INDIAN PHILOSOPHERS NAMED THESE PARTICLES ‘PARMANU’ WHEREAS THE GREEK PHILOSOPHERS NAMED THESE PARTICLES AS ATOMS ATOMS BY THE END OF THE 18TH CENTURY THE SCIENTIST BECAME INTERESTED TO KNOW MORE ABOUT THE COMPOUND, ATOMS AND STARTED THERE RESEARCH ABOUT THEM THEN ONE SCIENTIST NAMED ANTOINE LAVOISIER CAME UP WITH TWO MOST IMPORTANT LAWS OF CHEMICAL COMBINATION WHICH WERE LAW OF CONSTANT PROPORTIN AND LAW OF CONSERVATION OF MASS AND THESE LAWS WERE ONLY ESTABLISHED AFTER CONDUCTING VARIOUS EXPERIMENTS. SO NOW LET US TAKE A LOOK ON BOTH OF THESE LAWS THE FIRST LAW IS LAW OF CONSTANT PROPORTION. WHAT THIS LAW SIGNIFIES??? LET US HAVE A LOOK AT THIS LAW THIS LAW STATES THAT A PURE CHEMICAL COMPOUND ALWAYS CONSIST OF THE SAME ELEMENTS THAT ARE COMBINED TOGETHER IN A FIXED RATIO BY MASS FOR EXAMPLE LET US TAKE WATER WE KNOW THAT THE CHEMICAL NAME OF WATER IS H20 AND THE MASS OF ONE ATOM OF HYDROGEN IS 1 AND MASS OF ONE ATOM OF OXYGEN IS 16 THERE ARE TWO ATOMS OF HYDROGEN THEREFORE TOTAL MASS WILL BE 2 AND THERE IS ONE ATOM OF OXYGEN, THEREFORE TOTAL MASS WILL BE 16 AND AFTER FINDING THE RATIO OF HYDROGEN:OXYGEN YOU WILL FIND THAT THE RATIO COMES TO BE 1:8 THEREFORE THE RATIO BETWEEN ELEMENT IS 1:8 AND THIS RATIO WILL NEVER CHANGE NOW LET US TAKE EXAMPLE OF CARBON DIOXIDE WHICH IS COMPOSED OF CARBON AND OXYGEN AND ITS CHEMICAL NAME IS CO2 MASS OF ONE ATOM OF CARBON 12 AND MASS OF ONE ATOM OF OXYGEN IS 16. THERE IS 1 ATOM OF CARBON THEREFORE TOTAL MASS WILL BE 12 AND THERE ARE 2 ATOMS OF OXYGEN THEREFORE TOTAL MASS WILL BE 32. NOW AFTER FINDING THE RATIO OF CARBON:OXYGEN YOU WILL FIND THAT THERE RATIO IS 3:8 AND THIS RATIO BETWEEN ELEMENTS WILL NEVER CHANGE THEREFORE WE CAN CONCLUDE THAT THE RATIO OF THE ELEMENTS DOESN’T CHANGES AND THE COMPOPUND IS MADE UP OF ONLY THIS FIXED RATIO NOW LET US COME UPON THE SECOND LAW WHICH IS LAW OF CONSERVATION OF MASS. WHAT THIS LAW SIGNIFIES?? THIS LAW STATES THAT THE MASS CANNOT BE CREATED NOR BE DESTROYED IN A CHEMICAL REACTION AND THE TOTAL MASS OF REACTANTS BEFORE REACTION IS EQUAL TO THE TOTAL MASS OF THE COMPOUND FORMED AFTER REACTION FOR EXAMPLE, C+O2=CO2 HERE MASS OF CARBON IS 12 AND MASS OF OXYGEN IS 16, AFTER REACTION THE AMOUNT OF CARBON DIOXIDE PRODUCED WILL HAVE THE MASS 44 i.e, THE SUM OF MASS OF REACTANT BEFORE REACTION IS EQUAL TO THE SUM OF MASS OF COMPOUND AFTER REACTION NOW LET US COME UPON THE DALTON’S ATOMIC THEOREM ACCORDING TO THIS ALL MATTERS WETHER AN ELEMENT A COMPOUND OR A MIXTURE ARE COMPOSED OF SMALL PARTICLES CALLED ATOMS HE USED THE WORD ATOMS GIVEN BY THE GREEK PHILOSOPHERS. THE POSTULATES OF THIS THEORY ARE 1) ALL MATTER IS MADE UP OF VERY VERY SMALL PARTICLES CALLED ATOMS 2) ATOMS CAN’T BE DIVIDED FURTHER AND CANT BE CREATED NOR BE DESTROYED 3) ATOMS OF SAME ELEMENTS ARE IDENTICAL AND HAVE SAME MASS BUT 4) THE ATOMS OF DIFFERENT ELEMENTS HAVE DIFFERENT MASS AND HAVE DIFFERENT CHEMICAL PROPERTIES 5) ATOMS COMBINE IN RATIO OF SMALL NUMBER TO FORM COMPOUNDS 6) THE NUMBER AND KINDS OF ATOMS ARE CONSTANT IN A GIVEN COMPOUND

6 Replies to “atoms and molecules class-9”

  1. Molecules, Compounds, & Mixtures. Atoms can bond together into groups and form a molecule. If the molecule contains atoms of different types bonded together, we call it a compound

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