The boiling points need to differ by 50 degrees to enable their complete separation ie of two different liquids. The separation occurs by first evaporation of one of the liquids and then its condensation and collection. It is a physical process not a chemical one.
Answer:
1.) 3
2.) 60 CM
Explanation:
1. Density=
= 
2. Length*Width*Height=3*10*2
Mass number = protons + neutrons = 34+46 =80
the element with an atomic number of 34 and mass number of 80 is selenium
Oxygen carbon and hydrogen
16. FALSE
17. TRUE
18. FALSE
19. TRUE
20. TRUE
