Which of the following is true about the concept of half-life?
a. half-life measures the rate of decay of a radioisotope.
b. the shorter the half-life, the more dangerous the radioisotope.
c. half-life predicts which atoms in a radioactive sample will decay.
i think it`s a?

What happens when the temperature of a solution increases?

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н, о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false