I think the best answer that will describe chemical change is the first option. During a chemical change, b<span>oth the identity and the properties of a substance change because new substances are being formed by a chemical reaction. An example is rusting of steel</span>
I would personally convert the 12 mg to g so I could see what I was working with. So 12 mg to grams is 0.012 g...
so 1 tablet is 0.012g. the patient needs 0.024 g.
so 0.024g/0.012g = 2 tablets or 0.012g X 2 is 0.024 g
hope this helps :)
The test for this is fairly simple.
We take a glowing match or splint near the gas sample, if the glow intensifies, oxygen is present.
If a lit splint or match goes out with a popping sound, this means that hydrogen is present.