Bonjeur monseur, la french are here! it seems you have a problem with the elements on earth. lead seems correct since it is indeed a harmful material
<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Mole ratio is defined as the ratio between the stoichiometric coefficients of the molecules present in the chemical reaction.
For the given balanced chemical equation:

By Stoichiometry of the reaction:
3 moles of iron metal reacts with 4 moles of water to produce 1 mole of iron oxide and 4 moles of hydrogen gas.
The mole ratio of 
Hence, the correct answer is Option A.
False, gravity is a force, matter has mass and volume.
Answer:
Double replacement reaction
Explanation:
Now, let us first write the reaction equation properly:
H₂SO₄ + 2KOH ⇒ K₂SO₄ + 2H₂O
The above reaction is a neutralization reaction between an acid and a base whose product gives salt and water only at most instances.
From here, we can observe that the species displaces on another in their ionic state. Hydrogen replaces potassium and water is produced. Potassium combines chemically with sulfate ions to give the salt of potassium.