A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ___________. (Nearest integer)

(Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)

For a first order reaction A $$\to$$ B, the rate constant, k = 5.5 $$\times$$ 10^$$-$$14 s^$$-$$1. The time required for 67% completion of reaction is x $$\times$$ 10^$$-$$1 times the half life of reaction. The value of x is _____________ (Nearest integer)

(Given : log 3 = 0.4771)

It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be ____________ kJ mol^$$-$$1. [nearest integer]

(Given ln10 = 2.3, R = 8.3 J K^$$-$$1 mol^$$-$$1, log 2 = 0.30)

The rate constant for a first order reaction is given by the following equation:

$$\ln k = 33.24 - {{2.0 \times {{10}^4}\,K} \over T}$$

The activation energy for the reaction is given by ____________ kJ mol^$$-$$1. (In nearest integer) (Given : R = 8.3 J K^$$-$$1 mol^$$-$$1)