Copper choruses purpose is its used as a catalyst for organic and inorganic reactions , mordant for dyeing and printing textiles, pigment for glass and ceramics, wood preservative, disinfectant, insecticide, fungicide, and herbicide. (Not sure if you want the actual purpose of water or not)
Blue box. Gravitational potenti al energy<span> changes into kinetic </span>energy. The equation for gravitat ional potential energy<span> is GPE = mgh, where m i s the mass in kilograms, g is the a cceleration due to gravity (9.8 on Earth), and h is the height above the ground in meters</span>
The number of oxygen atoms are 6 atoms
<u><em>Explanation</em></u>
According to the law of mass conservation the number of reactant atoms is equal to number of product atoms.
For given equation to obey the law of mass conservation it need to be balanced as below
4 Al + 3 O₂ → 2 Al₂O₃
Al₂O₃ is the product,therefore the number of oxygen atom
= coefficient in front of Al₂O₃ × subscript of O
=2 x 3 = 6 atoms
390 because im cool and awsome