12, if the decimal is over five, round up. If it's not, round down. Not sure what you mean by significant figures.
Answer:
The amount of moles of Fe in 5.22*10²² atoms of Fe is 0.0867.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression. Avogadro's number applies to any substance.
Then you can apply the following rule of three: if 6.023*10²³ atoms are contained in 1 mole, 5.22*10²² atoms are contained in how many moles?

amount of moles= 0.0867
<u><em>The amount of moles of Fe in 5.22*10²² atoms of Fe is 0.0867.</em></u>
As atomic number increases atomic radii also increase down group 1. ionisation energy down group 1 will also decrease because as atomic radii gets bigger there is less electrostatic force between nuclei and electrons so less energy needed to remove valence electron.
Answer:
Three double bonds and no lone pairs of electrons- trigonal planar
Two single bonds and two lone pairs of electrons-bent
Five single bonds and no lone pairs of electrons- trigonal bipyramidal
Three single bonds and one lone pair of electrons- trigonal pyramidal
Two double bonds and no lone pairs of electrons - linear
Four single bonds and no lone pairs of electrons- tetrahedral
Six single bonds and no lone pairs of electrons- octahedral
Explanation:
The valence shell electron pair repulsion theory gives a description of the shape of a molecule based on the number of regions of electron density present on the valence shell of the central atom of the molecule.
The molecules are distorted away from the shape predicted on the basis of the VSEPR by the presence of lone pairs on the valence shell of the central atom in the molecule. In the absence of lone pairs, the shape of a molecule is exactly the shape predicted on the basis of the VSEPR theory.