Magnesium combined with chlorine.
How?
- Look at the question .Compound has -1 charge in it .Hence it contains Halogen.
- Looking at the options Option B and C contain Iodine and chlorine i.e halogens .
Now come to metals side.
- Potassium has valency 1(Look the Electronic configuration below)
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Hence it will contain +1 charge which is omitted directly .
Now come to option C.
- Magnesium has charge +2(Look at EC below

Hence the compound formed is given by

Hence option C is correct.
Answer:
When one object uses force to move the other.
Explanation:
This is called Thrust.Thrust is used in airplane engines,or an engine can be a source of Thrust,we use our legs to Thrust us forward when we walk!
<h3>Answer:</h3>
Oxidation number refers to a number given to an atom which shows the number of number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound.
Hence oxidation number of following atoms in given reaction are:
In NaOH:
Na = +1
O = -2
H = +1
In H2:
H = 0
Opportunity cost
Opportunity cost is the benefit, profit or value that could have been received or obtained but instead given up in favor of another alternative or course of action. Every situation has several alternatives and every resource has several alternative uses as well. Thus, every decision comes with it an opportunity cost. <span>
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