Statement 2 is correct.
solids moving into solution is a physical change as the core structure of the molecules remain the same. evaporation of water and crystallization of salt are both physical changes as well.
The water does not change it's H2O chemical makeup because salt was dissolved into it.
Answer:
Denitrification changes nitrogen into a gaseous form.
Explanation:
The order in which you would dig through the layers is
crust → upper mantle → lower mantle → outer core → inner core
See the image below.
Answer:
2Al(s) + 6HCl(aq) = 2AlCl3(aq) + 3H2(g)
Explanation:
The reaction is a displacement reaction.
The reaction does not commence immediately because the Al(aluminum) has Al2O3 (Aluminum oxide) which protect it from reacting with water.
It takes some time for the HCl (hydrochloric acid) to eat the coating, then the reaction proceed vigorously to produce hydrogen gas bubbles. Generally metals that are above hydrogen in the electrochemical series tend to displace Hydrogen from Hydrochloric acid. The more negative the electrochemical volts the more the tendency to lose electron. Metal above hydrogen have negative evolts while those below have positive evolts
