Context: The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance. Crystals of silicon are used, as they are available in high quality and purity by the technology developed for the semiconductor industry. The unit cell volume is calculated from the spacing between two crystal planes referred to as d220. The molar volume Vm(Si) requires a knowledge of the density of the crystal and the atomic weight of the silicon used. The Planck constant is given by

Question: What is the primary method for determining the Avogadro constant?
Answer: The X-ray crystal density method

Question: The Avogadro constant is determined to be the ratio between what two factors in the X-ray crystal density method?
Answer: the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance

Question: What element is used typically to establish Avogadro's constant?
Answer: Crystals of silicon

Question: How is unit cell volume calculated?
Answer: from the spacing between two crystal planes referred to as d220

Question: Calculating molar volume requires knowledge of what two factors?
Answer: the density of the crystal and the atomic weight of the silicon used

Question: What is the secondary method for determining the Avogadro equilibrium?
Answer: Unanswerable

Question: What element is typically used to establish Avogadro's formula?
Answer: Unanswerable

Question: How is unit nucleus volume calculated?
Answer: Unanswerable

Question: What two factors of knowledge are required to calculate solar volume?
Answer: Unanswerable

Question: What is not available in high quality and purity for the semiconductor industry?
Answer: Unanswerable