A crystal<span> or </span>crystalline solid<span> is a </span>solid<span> material whose constituents (such as </span>atoms<span>, </span>molecules<span> or </span>ions<span>) are arranged in a highly ordered microscopic structure, forming a </span>crystal lattice<span> that extends in all directions.</span><span> In addition, macroscopic </span>single crystals<span> are usually identifiable by their geometrical shape, consisting of flat </span>faces<span> with specific, characteristic orientations. example of it are ice, rocks , organigenic crystals</span>
Answer:
Density, 
Explanation:
The attached figure shows a 38.6 kg marble slab. The dimensions of the marble slab is 23 cm × 17 cm × 4 cm
Density = mass/volume
Volume of a cuboid shape is equal to, V = 23 cm × 17 cm × 4 cm
V = 1564 cm³
Density,

or

So, the density of the marble slab is
.
To convert grams to moles, you need molar mass.
according to the periodic table, the molar mass of 47.88 g/mol. answer is C