Answer:
Magnesium oxide is an ionic compound that can be used as a building material. MO2 is actually a raw material that used in producing cement for building houses, buildings, and other constructions.
Explanation:
The amount of Silicon left after 300 years is 75g
It is given that the initial amount of Si is 100 times decay is 300 years and the half-life of Silicon is 710 years.
The radioactive decay formula is given by,
A = A₀ x 2^(-t/h);
where;
A is the resulting amount after t time, Ao is the initial amt (t=0),t is the time of decay, and h is the half-life of the substance.
On substituting the values from the given we get,
A = 100x2^(-300/710)
A = 100 x 0.746112347
A = 74.6112347 grams left after 300 yrs
Therefore, the number of grams of silicon left after 300 years is 74.6112347g. This value could be rounded off to 75 grams as in the whole number
To know more about half-life, click below:
brainly.com/question/1160651
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I thinks it’s C don’t come for me if it’s wrong lol
Answer:
2.11 g hydrobromic acid (correct to 3SF)
Explanation:
Molecular formula of hydrobromic acid = C2H5BrO2
mass of C2H5BrO2 = 140.96g
Beginning with what we're given, 9.03*10^21 we then make a conversion by using Avegadro's number which is 6.02*10^23 per mole (Oct. 23 at 6:02 am is national mole day :) Then, we need to convert out of moles, 140.96g hydrombromic acid per mole.
It looks like this:
9.03*10^21 molecules • (1 mol C2H5BrO2 / 6.02*10^23 molecules) • (140g C2H5BrO2 / 1 mol) = 2.1144 g C2H5BrO2