Answer:
It is the way of cleaning of impurities present in metals
Answer: The correct option is A.
Explanation: In a chemical reaction, reactants react to form a number of products.
For the formation of products, the bonds of the individual reactants must be broken and the bonds of the products must be formed.
For example: Formation of water from hydrogen gas and oxygen gas. Reaction follows:

The Bonds of hydrogen and oxygen molecule are broken and new bonds between hydrogen and oxygen atoms are formed to give water molecule.
Answer:
$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Explanation:
Length of the room = l = 15.0 ft = 
Width of the room = w = 12.0 ft = 
(1 yard = 3 feet)
Area of the room = l × w = 
Cost for installing a carpet for a room = $10 per square yard
Cost for installing a carpet for a room wit area 20.0 square yard :

$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Answer:
The correct answer is cation. See the explanation below, please.
Explanation:
An atom with a net charge, either positive or negative, is called an ion. In the event that an atom loses an electron (or more), that is, it will have more protons than electrons, and its net charge will be positive, it will be called cation. In the opposite direction, if an atom gains electrons, it will have a negative net charge, called anion.