Answer:The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing
Explanation:
Depends on the cut if its like a pimple You could use chap stick but if its a deep cut you should probably get it checked out/ use a lot of pressure and hold a clean rag over the cut. if its a little scrape clean it with alcohol and put some napkin over it and then a bandaid
Answer:

Explanation:
We already know that the mass number of an atom is the sum of the number of protons and the number of neutrons.
So, the mass number of this isotope is;
Number of protons = 7
Number of neutrons = 8
Mass number = 7 + 8 = 15
Hence, the isotope is;

Answer: Crystals are formed by the earth and the earth itself otherwise then its a fake crystal
Explanation:
Every crystal that exists was formed when earth was formed. Take diamonds for example, All diamonds were crushed for millions of years by the earth and that's why they are so valuable. All diamonds are just coal.
So your answer is no but fake crystals yes
Density of a liquid determines how it will layer (heaviest to lightest). If the liquid is least dense it will float to the bottom. Layers will remain separated because each liquid is actually floating on top of the more dense liquid beneath it.