The atomic number of Neon is 10. The atomic number of Calcium is 20. Compared with a mole of neon, a mole of calcium contains

Comparing 1 mole of Neon to 1 mole of calcium, both substances contains  

6.0221 x 10²³  atoms.

The atomic number of neon is 10 and the atomic number of calcium is 20.

The atomic number of an atom is the number of proton of an atom.

1 mole of Neon can be represented as follows

Ne

1 mole of Calcium  can be represented as follows:

Ca

Avogadro's number, or Avogadro's constant, is the number of particles found in one mole of a substance.

This experimentally determined value is approximately 6.0221 x 10²³ particles per mole.

This means 1 mole of any substance contain 6.0221 x 10²³  atoms.

Comparing 1 mole of Neon to 1 mole of calcium, both substances contains  

6.0221 x 10²³  atoms.

learn more on atomic number : link

an equal number of atoms

Explanation:

One mole of a substance contains the Avogadro's number of elementary entities (Atoms, molecules,  ion, etc).

Hence, one mole of calcium and one  mole of neon will contain exactly the same number of atoms which is 6.02 *10^23 atoms. This is known as the Avogadro's number.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.