There are billions of stars in the known universe. None of them seem to be as bright as the Sun. Which statement gives the best reason why the Sun appears to be the brightest star? A. All-stars have the same apparent brightness, but the Sun has more absolute brightness. B. The Sun is the biggest of all the stars and therefore has the greatest absolute brightness. C. The Sun is the hottest of all the stars and therefore has the greatest absolute brightness. D. The Sun is the closest star to Earth and so it seems brighter than distant stars that have much greater absolute brightness.

The answer is D. The Sun is the closest star to Earth and so it seems brighter than distant stars that have much greater absolute brightness.

Explanation: Stars like red super giants like beetleguise are way brighter and bigger than the sun, but the sun is closest to the earth. It is only in its main sequence stage but seems bright because of its short distance from the sun( 93 million miles).

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

coral.

explanation:

coral. many marine organisms that produce calcium carbonate shells or skeletons are negatively impacted by increasing co2 levels and decreasing ph in seawater.