Water is different from other substances
because:
a it is more dense as a solid than a liquid
b it is less dense as a solid than liquid
c it is more dense as a gas than a liquid
d it is less dense as a solid than a gas

Option (b) is the correct answer.

Explanation:

It is known that density is the amount of mass divided by volume.

When water is present in solid state that is, in the form of ice then its molecules arrange themselves in a rigid tetrahedral structure.

Due to this there will cage like spaces between the molecules of ice during the bonding. As a result, they occupy more volume and it is known that density is inversely proportional to volume.

Hence, ice has low density as compared to liquid state of water.

When water is present in liquid state, then its molecules are closer to each other and they are able to slide past each other. Hence, space between them is less therefore, lesser will be its volume.

As a result, liquid state of water will have more density.

Thus, we can conclude that water is different from other substances  because it is less dense as a solid than liquid.

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

your parents i think this could be it