How many atoms are contained in 0.257 moles of silver

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

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What does the mass of 0.7891 mol of ferric oxide (fe2o3)