Periodic Table and Trends Flashcards
Identify the name
Group 1A
Alkali metals
soft metallic solds; lowest ionization energies (very reactive); e.g. K
Identify the name
Group 2A
Alkaline earth metals
harder, more dense, and higher MP than 1A metals; low IE e.g. Be, Mg, Ca
Identify the name
Group 6A
Chalcogens
Covalency of 2, high EA and EN e.g. O, S, Se, Te, Po, Lv
Identify the name
Group 7A
Halogens
Highest electronegativity and affinity across a period; 1 covalency
Identify the name
Group 8A
Noble gases
stable electron configuration; octet; inert; unreactive e.g. He, Ne, Ar
What’s the trend for…
Atomic radii
across a period and down a group
- decreasing across a period
- increasing down a group
What’s the trend for…
Ionic Radii
Charged atoms relative to parent atoms
- Cations < parent atom
- Anion > parent atom
cations - replusions reduced; attracted
anions- increase repulsion
Ionic Radii Trend
For ions carrying the same charge, ionic radius ________ top to bottom
increases
increasing n
Ionic Radii Trend
For isoelectronic series, as atomic number increases, ionic radius ________?
decreases
Same number of valence e- but increasing nuclear charge
What is Ionization Energy (IE)?
the minimum energy required to remove an electron
an endothermic process with the unit kJ/mol
What’s the trend for…
Ionization Energy
- increases across a period
- decreases down the group
smaller atoms, higher IE.
Factors: Zeff + distance from nucleus
For succesive ionization energies, IE ____?
Increases.
I1 < I2 < I3
Ion becomes positive. Closer to nucles, higher Zeff, higher IE
Define Electron Affinity (EA)
measures the attraction of the atom for the added electrons
Usually exothermic.
Greater affinity, more negative EA.
Electron Affinity
Contrast 1st EA and 2nd EA
1st EA = –
2nd EA = +
Positive value means higher in energy thus, unstable. More repulsion.
What is Electronegativity?
the power of an atom of the element to attract electrons to itself in a compound
