How do scientists measure the idea of time so long ago?
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<h2>Hey There!</h2><h2>____________________________________</h2><h2>Answer:</h2>
The periodic table, arranges the chemical elements ascording to their recurring properties. The number of each element corresponds to the number of protons in its nucleus.
<h3>-------------------------------------------------------------------------------------------</h3><h3>Groups and Periods</h3>There are 8 groups and 7 periods in the periodic table.
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Each element within a group has similar physical or chemical properties because of its atom's outermost electron shell. The outermost shell of every element in a specific group has same number of valence shell (most chemical properties are determined by the the outermost valence shell electron). The group number of an element represents the number of electrons in its outermost orbit. This shows that elements arranged in the same group have the same number of electrons in their outermost orbit.
<h2>_____________________________________</h2><h3>Sodium and Potassium</h3>Sodium and Potassium belong to the same group i.e. GROUP 1 which is also called S BLOCK Group or IONIC GROUP. They have the similar properties,
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Properties of S block Elements
1- They are soft metals
2- possess low melting and boiling points
3- They have the largest atomic radii in their corresponding periods
4- are good conductors of heat and electricity.
5- They have low values of ionization energies and are hence highly electropositive.
<h2>_____________________________________</h2><h2>Best Regards,</h2><h2>'Borz'</h2><h2 />
Explanation:
The given data is as follows.
Energy needed for 1 mole = 279.7 kJ =
= 279700 J
Therefore, energy required for 1 atom will be calculated as follows.
=
As relation between energy and wavelength is as follows.
E =
where, h = planck constant =
c = speed of light =
= wavelength
Therefore, putting given values into the above formula as follows.
E =
=
=
or, = m
= 428 nm
Thus, we can conclude that the maximum wavelength of light that can remove an electron from an atom on the surface of lithium metal is 428 nm.