The half-life of gold-198 is 2.7 days. After
amount of gold-198 will remain.
days, 1/4 of the original

8.1 days

Explanation:

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant = x

a - x = amount left after decay process=  

a) to find rate constant

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

b) for completion of one fourth of reaction

Thus after 8.1 days , one fourth of original amount will remain.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i