They are <span>Common Soil </span><em>Bacteria</em><span> Nematodes.
Hope this helps:)</span>
The chemical properties, chemical reactivity
Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life is represented by 

= rate constant
Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.
As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.
A polar molecule is a molecule whose ends have opposite electric charges. An example of a polar molecule is H2O or water. Water has 1 side which is positive and the other side which is negative. It is a dipole which means that the two sides are not having the same charges.