Cross section of interaction in elastic interaction model ========================================================= The effective cross section is a physical quantity characterizing the probability of transition of a system of two interacting particles to a certain final state, a quantitative characteristic of the acts of collision of particles of a stream hitting a target with target particles. The effective cross-section has the dimension of the area. **Links:** #. `Wikipedia `__. .. TODO: find English link .. py:currentmodule:: symplyphysics.laws.chemistry.cross_section_of_interaction_in_elastic_interaction_model .. py:data:: cross_sectional_area_of_interaction :attr:`~symplyphysics.symbols.chemistry.cross_section` of interaction of particles. Symbol: :code:`sigma` Latex: :math:`\sigma` Dimension: :code:`area` .. py:data:: particle_diameter :attr:`~symplyphysics.symbols.classical_mechanics.diameter` of a gas particle. Symbol: :code:`D` Latex: :math:`D` Dimension: :code:`length` .. py:data:: sutherland_constant :attr:`~symplyphysics.symbols.thermodynamics.sutherland_constant` of the gas. Symbol: :code:`S` Latex: :math:`S` Dimension: :code:`temperature` .. py:data:: temperature :attr:`~symplyphysics.symbols.thermodynamics.temperature` of the gas. Symbol: :code:`T` Latex: :math:`T` Dimension: :code:`temperature` .. py:data:: law :code:`sigma = pi * D^2 * (1 + S / T)` Latex: .. math:: \sigma = \pi D^{2} \left(1 + \frac{S}{T}\right)