Answer:
Two-third of the toxic metal, mercury comes from gold mining.
Explanation:
During gold mining small pieces of gold which are within the soil are separated with the help of mercury. Both gold and mercury are mixed and they forms amalgam. Further gold can be extracted by vaporizing the mercury, thus releasing it into air and contributing to two-third of the air pollution by human activities.
Therefore (d) gold mining is the correct answer.
Answer:
11,700
Explanation:
Since the exponent is negative you move the decimal point to the right.
The question is incorrect, nitration of methylbenzoate occurs at 3 position to get, methyl 3-nitrobenzoate.
This is because, in present reaction the reactant i.e. methylbenzoate, has low electron density at m-position.
Due to this, NO2+ prefentially attaches m-position to form methyl 3-nitro benzoate as the product.
A detailed reaction mechanism for formation of product is provided below.
In chemical equilibrium, radioactive decay occurs because of unstability due to the high neutron-to-proton ratio. Through time, the radioactive element is converted to a new element. This radioactive decay undergoes first order reaction. Its equation is in the form of
A = A₀e^(-kt), where A is the amount of the element after time t, A₀ is the original amount of element at t=0 and k is the rate constant.
Half-life is the amount of time for A to be 1/2 of A₀. Modifying the equation during half time, we let A=1/2 A₀. Then.
1/2 A₀ = A₀e^(-kt)
1/2 = e^(-k(5730))
k = 0.000121
Thus, the first-order rate constant is equal to 0.000121 per year.
Answer:
Absolutely correct
Explanation:
Displacement is vector i.e. it deals with magnitude and direction WHILE Distance is scalar i.e. it only deals with magnitude
