Answer:
Two-third of the toxic metal, mercury comes from gold mining.
Explanation:
During gold mining small pieces of gold which are within the soil are separated with the help of mercury. Both gold and mercury are mixed and they forms amalgam. Further gold can be extracted by vaporizing the mercury, thus releasing it into air and contributing to two-third of the air pollution by human activities.
Therefore (d) gold mining is the correct answer.
Answer:
the mass number is 40 g/mole
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Answer:
13g
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction.
Therefore, if the total mass of the products is 30g, that means that the reactants have a mass of 17g + the other reactant to = 30g.
30g - 17g = 13g