Question

Element in period 3 wch has gh electon affinity and electrone gativity

Answer 1

Element Proton number Symbol Electronegativity
(scale 0 to 4)
sodium 11 Na 0.9
magnesium 12 Mg 1.2
aluminium 13 Al 1.5
silicon 14 Si 1.8
phosphorus 15 P 2.1
sulphur 16 S 2.5
chlorine 17 Cl 3.0
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Graph of physical data
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Explanation of this trend
Electronegativity is the relative ability of an
atom to attract the bonding electron pair in a
covalent bond (to withdraw electron density).
It cannot be measured directly. In the Pauling
electronegativity index, the most
electronegative element (fluorine) is given an
electronegativity value of 4. Note that there
are no values for the noble gases (Group 0)
as they do not usually form covalent bonds.
Find out more about electronegativity
at Electronegativity Totally Explained.
Going across Period 3:
the nuclear charge increases ...
the atomic radius decreases ...
there are more electrons, but the increase in
shielding is negligible because each extra
electron enters the same principal energy level
...
so electrons will be more strongly attracted to
the nucleus.
Remember that ionisation energies are all
endothermic processes (i.e. energy is needed
to remove electrons), so atoms with low
electronegativities do not have a tendency to
lose electrons. They just have a weaker
tendency than other atoms to attract the
bonding electron pair in a covalent bond.
In Period 3, sodium with 11 protons is the
least electronegative element, and chlorine
with 17 protons is the most electronegative
element. You might expect argon (with 18
electrons) to be the most electronegative
element in Period 3, but its outer energy levels
are full. Therefore, it does not form covalent
bonds with other atoms, so it is given an
electronegativity value of zero.