Where are the following elements to choose from?
Answer:
91.2 nm
Explanation:
The Rydberg equation is given by the formula
1/ λ = Rh ( 1/ n₁² - 1/ n₂²)
where
λ is the wavelength
Rh is Rydberg constant
and n₁ and n₂ are the energy levels of the transion.
We can see from this equation that the wavelength is inversely proportional to the difference of the squares of the inverse of the quantum numbers n₁ and n₂. It follows then that the smallest wavelength will be given when the the transitions are between the greatest separation between n₁ and n₂ whicg occurs when n1= 1 and n₂= ∞ , that is the greater the separation in energy levels the shorter the wavelength.
Substituting for n₁ and n₂ and solving for λ :
1/λ = 1.0974 x 10⁷ m⁻¹ x ( 1/1² -1/ ∞²) = 1.0974 x 10⁷ m⁻¹ x ( 1/1² - 0) =
λ = 1/1.0974 x 10⁷ m = 9.1 x 10⁻8 m = 91.2 nm
Answer:
All three states of matter (solid, liquid and gas) expand when heated. The atoms themselves do not expand, but the volume they take up does.
When a solid is heated, its atoms vibrate faster about their fixed points. The relative increase in the size of solids when heated is therefore small. Metal railway tracks have small gaps so that when the sun heats them, the tracks expand into these gaps and don’t buckle.
Liquids expand for the same reason, but because the bonds between separate molecules are usually less tight they expand more than solids. This is the principle behind liquid-in-glass thermometers. An increase in temperature results in the expansion of the liquid which means it rises up the glass.
Molecules within gases are further apart and weakly attracted to each other. Heat causes the molecules to move faster, (heat energy is converted to kinetic energy) which means that the volume of a gas increases more than the volume of a solid or liquid.
However, gases that are contained in a fixed volume cannot expand - and so increases in temperature result in increases in pressure.:
Dispersion forces or London dispersion forces are collectively referred to as Van der Waals forces. These forces are temporary and arise from the relative position of electrons in one atom to another. If the electrons become distributed in an asymmetrical manner, the negative charge is concentrated at one end of the particle and a positive charge is concentrated at the other. These forces are also called induced dipole-induced dipole attraction.
