Group.... because elements in a group have same chemical properties
An ionic compound is the attraction between a metal and a nonmetal!!
Answer: Measuring the age of fingerprints is important because it can help detectives on a crime.
With fingerprints you can find the criminals record. Which would lead to their eventual arrest and a solved case.
Explanation:
Carbon-14 and Uranium-238 have something we call a half live, which is basically a known time period for it to change half of its C-14 or U-238 radioactively decay. Since we know how long that is 5730 years for Carbon-14 for half a sample to deteriorate, than we can figure out how old it is.