Answer:
Sand may be deposited as sediments that become sedimentary rocks after hardening, or lithifying. Extreme burial pressure, rising temperature at depth, and a lot of time, will transform just about any rock to become a metamorphic rock.
Explanation:
The answer would be periods 6-7 :)
Answer:
hydrogen and oxygen to form water
Activation energy is the energy required by reactants to undergo chemical reaction and given products
Every reactant has some internal energy (sum of all kind of energy like kinetic energy, potential energy, mechanical energy, chemical energy etc). It needs some extra energy to undergo chemical reaction which is activation energy
All kinds of reaction whether exothermic or endothermic needs activation energy
Threshold energy = internal energy + activation energy