We can characterize properties of a substance to identify it because it helps us determine how the substance should be used. We can identify a substance by using physical or chemical properties. These help us by telling us which chemical we are looking at.
I hope this helps.. I wasn't sure what kind of answer you were looking for.
Answer:
1. Ca 2.element
2.H2O 4. Compound
3. nuclear decay 8. fission
4. nuclear synthesis 7. fusion
5.η 1. neutron
6.positive energy 6. proton
7.e 3. electron
8.number of protons in nucleus 5. Atomic number
