Answer:
The correct answer is - A matter that has an ordered arrangement of atoms, molecules, or ions.
Explanation:
In physics, a crystal is a type of solid matter in which a highly arranged molecule or atoms present to form a lattice that extended in all directions. It is a lightweight clear solid which is normally is colorless.
It can be cubic, hexagonal, triclinic, monoclinic, orthorhombic, tetragonal, and trigonal that are ordered arrangments. Its internal symmetry is visible to its surface.
Explanation:
speed of wave
v = wavelength x frequency
since frequency is f = 1/Period then
v = wavelength : Period
v = 10 cm/ 0.2 s = 50 cm/s
v = 0.5 m/s
