What is the mass in grams
of 2.25 mol of the element
iron, Fe?

126g

Explanation:

Data obtained from the question include:

Mole of Fe = 2.5moles

Molar Mass of Fe = 56g/mol

Mass of Fe =?

Number of mole = Mass/Molar Mass

Mass = number of mole x molar Mass

Mass of Fe = 2.25 x 56

Mass of Fe = 126g

Therefore, the mass in 2.25mol of Fe is 126g

126g

Explanation:

No of moles = mass given/molar mass

No of moles given=2.25mol

Molar mass of Fe= 56

Mass =?

Substitute the values into the formula

No of moles = mass given/molar mass

2.25= mass/56

Mass= 56×2.25

Mass = 126g

Mass of Fe in 2.25mols is 126g

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

it is stable as it is in group 0 which have full outer shells of electrons