Answer: The 3rd one
Explanation: Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.
I might be wrong
At the beginning there was just
1 mole of hydrogen and
1 mole of iodin.
The reaction goes:
One mole of hydrogen goes with one mole of iodin, creating
2 moles of product.
If 0.8 of hydrogen remaind, it means that
1-0.8=0.2 reacted.
So:
1 mole H2 react with 1 mole I2 creating 2 moles of products.
So 0.2 of hydrogen reacted with 0.2 mole of iodin creating 0.4 moles.
The mass of MgO needed to produce 4.8 tonnes of Mg is
8 tonnes or 2,000 Kg or 2,000 ,000 g
calculation
Si + 2 MgO = SiO2 +2 Mg
step 1 :find the moles of Mg
moles = mass/molar mass
mass = 4.8 tonnes = 480,000 g
molar mass = 24 g/mol
moles is therefore = 480,000 g/24g/mol = 200,000 moles
then by use of mole ratio between MgO to Mg which is 1:1 therefore the moles of MgO is also = 200,000 moles
mass of MgO = moles of MgO x molar mass of MgO
molar mass of MgO = 24 + 16 =40 g/mol
therefore the mass = 200,000 moles x 40 g/mol = 8,000,000 grams or 8,000,000/1000= 8,000 Kg or 8,000/1000 = 8 tonnes