Why does radiation decrease over time? A. As each normal atom decays into a radioactive atom, there are less
normal atoms left to decay.
B. Radioactive particles have a similar charge and as time goes on they
repel each other away.
C. Radiation occurs randomly and as more atoms decay there are less left
to spontaneously decay.
D. Radiation is derived from the concentration of radioactive atoms and the
concentration decreases as radioactive particles are emitted.

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.