Properties of Elements
The periodic table groups generally by composition and function.
NaCl is an ionic bond which is when one or more electron is transferred between the
elements. Na gives up an electron while Cl gains one; electrostatic attraction.
H is a covalent bond, a sharing of electrons which may not be equal.
Balance between charge of protons attracting electrons and electrons pushing away other
Coulomb’s Law is F(r) = (g g )/(1 2E r ) 0 2
g = charges
r = distance
E = permittivity of vacuum
++ positive repulsive
+ negative sttractive
Potential Energy is V(r) = (g g 1 24piE r) 0
Total E = KE + PE = 0.5mv (g g )/(1 2E r) 0
*strength that holds electron : to remove electron from H, +13.6 electron volts is needed
Ionization Energy: minimum energy required to remove an electron from a neutral atom
in the gas phase and form a positively charged ion.
X (g) (g) + e
*****ALWAYS POSITIVE AMOUNT OF ENERGY TO REMOVE
He needs 24.6 eV, Ne needs 21.6 eV, and Ar needs 15.8 eV.
Larger atoms have more electrons and the electrons are further from
the core while outer electrons are shielding the core. This means that
it is easier to remove the electrons (less energy required). + 2+
Second Ionization Energy: X ▯X (g) (g) + e
Always larger than the first ionization energy.
More protons and electrons attracting each other needing more energy.
Be +Be + +2 9.32 eV
Be ▯Be 18.21 eV
Be ▯Be +3 153.89 eV (Taking from core shell needs a lot of energy)
F ▯F +1 + 1e 17.42 eV
F ▯F 34.97
F ▯F +3 62.71
F +4▯F +5 87.14
F ▯F 114.24
F ▯F +6 157.16
F ▯F 185.78
F ▯F +8 953.85