The atomic number, the number of protons and the number of electrons.
Answer:
The separation between layers of atoms in the crystal is 164.52 pm.
Explanation:
Formula used
(Bragg's law)
Where :
n = an order of reflection (integer)
= wavelength of the beam incident X-ray
d = spacing between the layer
θ = incident angle ( angle between ray and scatter plane)
We have :
λ = 157 pm
θ = 28.5°
n = 1
d = ?
(Bragg's law)

The separation between layers of atoms in the crystal is 164.52 pm.
The answer is: another name for groups of elements is family.
There are 18 numbered groups in the periodic table.
The elements in a group have similar physical or chemical characteristics and some groups have a specific name, for example group 17 (the halogens).
Elements in the group have the same number of valence electrons, for example, chemical elements in group 15 of the periodic table have neutral atom with a valence electron configuration of ns²np³.
Explanation:The scientific inquiry process is the process in which scientists or researchers find an explanation for any natural world phenomena with logic and evidence collected by the systemic method or work.
The scientific inquiry process begins with a question or thinking (observation) for any natural phenomena like why freshwater has low albedo where ice has a high albedo percentage.