Answer:
w/w means weight/weight
Therefore, in a 250 g of solution, 5% needs to be KCl,
i.e. 5% x 250 = 12.5 g of KCl is needed.
For the answer to the question above,
1∙5µm² = ? m²
1m * 1m = 1m² But 1m = 1,000,000µm = 1x 10^6µm 1x10^6µm * 1x10^6µm = 1m² 1x 10^12µm² = 1m² (Now, try dividing both sides by 1x10^12). 1x10^12µm² /(1x10^12) = 1m² /(1x10^12) 1µm² = 0∙000 000 000 001 m² (multiply both sides by by 1∙5). 1∙5µm² = 0∙000 000 000 0015 m²
1∙5µm² = 1∙5x 10^-12 m²
I hope this helps
Answer : The correct answer is A. Nuclear reactors using Pu-239
B. burning coal
The sources which are not renewable are known as "non- renewable sources of energy .
Non - renewable sources are those which get expired after rapid use and can never be reproduced . These sources replenishes in very long time . Examples : Coal , petrol or fuels etc .
1) Nuclear reactors using Pu-239 : Nuclear reactors uses radioactive elements like uranium , plutonium etc , which are present in limit . after frequent use of these elements , they will vanish off , Hence we can say nuclear reactors are Non renewable source of energy .
2) Burning coal : Coal is used as one of the major source of fuel . On rapid utilization of coal they will finished from earth . It takes thousand of year for formation of coal . Hence , it is a Non -renewable source .
3) Photo-voltaic cell: These are cells which used solar energy . Solar energy is obtained from sun . Hence solar energy is renewable source of energy so is the photo voltaic cell .
4) Geothermal energy : Geothermal energy is source of energy that is extracted from earth's thermal energy . Since thermal energy of earth is present in very large amount and can be reproduced , hence it renewable source of energy .
5)Wind energy : Wind energy is source of energy that is obtained from wind. And wind is renewable source so the wine energy too .
Consequently , we can say only two of them " Nuclear reactors and burning of coal " are Non renewable force of energy .
Idk but here something that made my day
