How many calcium atoms would be in a 100 g sample of calcium

 The number of calcium  atoms  that would  be in a  100 g sample of calcium  is 1.505 x 10²⁴  atoms

     calculation

Step 1 ; find the  moles of calcium

moles = mass÷  molar mass

from periodic table the  molar mass of Ca =40 g/mol

moles is therefore = 100 g÷ 40 g/mol = 2.5 moles

Step 2: use the Avogadro's  law constant to determine the number of atoms  of Calcium

That is According  Avogadro's law   1 mole = 6.02 × 10²³  atoms

                                                           2.5 moles=? atoms

 {(2.5  moles  ×  6.02×10²³  atoms)  / 1 mole}  = 1.505  ×  10²⁴  atoms

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be