Periodic trend in melting points
Across Period 2 and Period 3,
Melting point increases from Group 1 to Group 4 (14)
Groups 1 to 3 (13) have metallic bonding which increases in strength due to increased forces of attraction
attra
between more
electrons in the outer shell that are released to the sea of electrons and a smaller positive ion
Group 4 (14) has a giant covalent structure with many strong covalent bonds requiring a lot of energy to overcome
A sharp decrease in melting
ng point from Group 4 (14) to Group 5 (15)
Groups 5 (15) to 0 (18) have simple molecular structures with weak London forces between molecules requiring little
energy to overcome
Trend in melting points across Periods 2 and 3
PERIODIC TRENDS PRACTICE QUESTIONS:
1)
B Al Ga In
a) Most metallic?
b) Least metallic?
c) Lowest electronegativity?
d) Highest ionization energy?
e) Largest atomic radius?
f) Which are non-metals?
g) Which are conductors?
h) Highest shielding effect?
g) List them in order from small to large.
h) Would they gain or lose electrons to form ions?
i) What charge would the ion have?
1) Would these be considered cations or anions?
m) Would the ion be larger or smaller than the atom?
In each set, tell which is larger AND why.
Ca v. K
O and O2-
Arrange the following elements in order of decreasing atomic size:
S, Cl, Al, Na
Arrange the following elements in order of increasing ionization energy:
Be, Mg, Sr
In each of the following pairs, which element is the most electronegative?
chlorine, fluorine
magnesium, neon
Give the name the element found at each of the following locations on the periodic table:
Group 1, period 4.
Group 13, period 3.
Write the symbols for the members of the following groups:
alkali metals
noble gases