The correct choice is B.
Mixtures retain their properties because science has proven it. Take a bag of trail mix for example. Those raisins and marshmallows and m&m’s can each be separated. When you take them out, they keep their same texture.
Is not correct because mixtures can be solids (Trail mix is one example)
Correct
Is not correct because sometimes it cannot be seen (Lemonade powder and water is one example)
Is not correct because trail mix is an example.
7. An exothermic reaction
8. The bonds are forming
Explanation:
Start with a balanced equation.
2H2 + O2 → 2H2O
Assuming that H2 is in excess, multiply the given moles H2O by the mole ratio between O2 and H2O in the balanced equation so that moles H2O cancel.
5 mol H2O × (1 mol O2/2 mol H2O) = 2.5 mol O2
Answer: 2.5 mol O2 are needed to make 5 mol H2O, assuming H2 is in excess.
Hidrogen gas is a diatomic gas, this is H2, which means that one molecule of gas has two atoms (every molecule of hydrogen gas consists in H2).
The particles in gases are the molecules, not atoms.
So, every molecule is a particle, and when you are told that you have 1 mole of hygrogen gas means that you have 1 mole of H2 molecules which is the same that 1 mole of particles.
Therefore, the answer is one mole.