Answer:Oxygen
Explanation:
Oxygen gets reduced when iron is oxidized.
Answer:
3,85 g of Fe
Explanation:
1- The first thing to do is calculate the molar mass of the Fe2O3 compound. With the help of a periodic table, the weights of the atoms are searched, and the sum is made:
Molar mass of Fe2O3 = (2 x mass of Fe) + (3 x mass of O) = 2 x 55.88 g + 3 x 15.99 g = 159.65 g / mol
Then, one mole of Fe2O3 has a mass of 159.65 grams.
2- Then, the relationship between the Fe2O3 that will react and the iron to be produced. With the previous calculation, we can say that with one mole of Fe2O3, two moles of Fe can be produced. Passing this relationship to the molar masses, it would be as follows:
1 mole of Fe2O3_____ 2 moles of Fe
159.65 g of Fe2O3_____ 111.76 g of Fe
3- Finally, the calculation of the mass that can be produced of Fe is made, starting from 5.50 g of Fe2O3
159.65 g of Fe2O3 _____ 111.76 g of Fe
5.50 g of Fe2O3 ______ X = 3.85 g of Fe
<em>Calculation: 5.50 g x 111.76 g / 159.65 g = 3.85 g
</em>
The answer is that 3.85 g of Fe can be produced when 5.50 g of Fe2O3 react
Answer: (E) 300 bq
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is represented by 
Half life of Thallium-208 = 3.053 min
Thus after 9 minutes , three half lives will be passed, after ist half life, the activity would be reduced to half of original i.e. 
, after second half life, the activity would be reduced to half of 1200 i.e. 
, and after third half life, the activity would be reduced to half of 600 i.e. 
,
Thus the activity 9 minutes later is 300 bq.
