Asample contains 16.75 g of the radioisotope u-236 and 50.25 g of its daughter isotope, th-232. how long did it take for decay to take place if one half-life of u-236 is 23 million years? 46 million years 69 million years 92 million years 115 million years

46 million years

Explanation:

The initial concentration of U-236 = the remaining concentration U-236 + the produced concentration of Th-232 = 16.75 g + 50.25 g = 67.0 g.

∵ U-236 has a half life of 23 million years.

67.0 grams of U-236 → (first half life = 23 million years) [33.5 grams of U-236  + 33.5 grams of Th-232] → (second half life = 23 million years) [16.75 grams of U-236  + 50.25 grams of Th-232].

So, it reaches the proposed concentrations after 2 half-lives = 2(23 million years) = 46 million years.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).