<span>1. The investigator should use fluorescent fingerprint powder, so that the prints will be visible on the dark surface when a special kind of light is used.
2. A possible cause of death would be asphyxia, and is one of the most common causes of death that involve murder and violence.
3. C. thin layer chromatography and Infrared spectrometry
</span>
The two are potassium and rubidium. Why? Na is an alkali metal. As you go down the metals become more reactive.
Calcium has 20 protons. Why? The atomic # is 20 (the one at the top).
It has 20 neutrons. Why? The atomic mass (the number on the bottom) is ~40, ignoring electron mass. 40- 20 protons = 20 neutrons.
It has 20 electrons.
Why? The # of protons and electrons is the same. Ions aren't on the periodic table.
Please mark brainliest if I helped you!
W a t e r ahhhh 8228c+x Skansen 2828