Rocks, rocks can be used for many things depending on which rock you are talking about some rocks are used for construction of cement mixtures. Granite and marble are used for counter tops and desks depending on what district you go to school in and how funded the schools are there. pumice is a rock found in waters around volcanoes and is used to smooth organic surfaces such as feet. miscellaneous rocks are also used to prevent erosion. non living things can also include carbon which is the bases of life itself. Carbon is an organic element which is used in the synthesis medicines such as aspirin and poisons such as dichloromethane which is not used to poison others but is toxic to humans, it is mainly used for different isolation of unknown substances. Depending on what R grouping is attached to the carbon can be the deciding factor of how it can be used and how it can react with the environment. Elements like helium can be used in gas chromatograms and put into balloons
Elements are like loners, compounds are like couples, and mixtures are like a group of friends that can also have couples (compounds)
Ln(800/3200) = - kt
t = 24 years.
ln(0.25) = -k*24
(- 1.3863) = -k*24
1.3863 / 24 = k
0.05776 = k
ln(0.5) = -k*t
-0.6931 = - 0.05776 t
12 = t
I don't know if you can just look at the question and know the answer. If 24 years is a quarter life then is it obvious that the 1/2 life is 12 years? It might be, but the method I've used works for sure.
