একটি সংখ্যা, এটি থেকে 15 বিয়োগ করলে, তার 80% এ ফিরে আসে। সংখ্যার 40% কত? | শ্রেণী 14...

In limestone,40% is calcium and the rest is carbon and oxygen.If in 20kg of limestone, there is 9.4kg of oxygen,ten what is the percentage of carbon in it? 12% b.13% c.14% d.15%

Electrolytic reduction of 6.15 g of nitrobenzene using a current efficiency of 40% will require which of the following quantity of electricity? [C =12, H=1, N=14,O=16]

Photosysthesis si a bio process by which plants make energy rich molecules from low energy molecules with the help of energy from sunlight . The photosysthesis of glucose can be represented as: 6CO_(2(g))+ 6H_(2)O_(g) + hv rarr C_(5)H_(12)O_(6(s)) + 6O_(2)(g)..........(i) The energy of one mole of a photon of wave lenght is known as one Einstein. On an average , solar radiation 7 xx 10^(14) kg of glucose annually on earth . Calculate the annual decrease in the CO_(2) level in the troposphere in ppm , due to photosynthesis. (1 ppm=1 g of CO_(2) per 10^(3) kg of air in troposhere). Assume that the total mass of air envolope surrounding the earth is 5.0 xx 10^(15) kg and 80% of its is present in the tropsphere.