main group Flashcards
(30 cards)
main group elements
everything except for transition metals, lanthanides, and actinides
atomic radius periodic trend
increases down a column, decreases left to right across row
electronegativity periodic trend
increases down a column, increases left to right across a row
metallic character periodic trend
increases down a column, decreases left to right across a row
lightest element in each family
smaller atomic radius, different chemistry than rest of family
Alkali metals
Li, Na, K, Rb, Cs, Fr
Characteristics of Alkali metals
- common O.S. =+1
- highly reactive (valence e- easily given up)
-reacts w oxygen to form oxides (Li) peroxides (Na) and superoxides (K, Rb, Cs) - lightest element (H) not part of family
characteristics of Hydrogen
- lightest element, escapes from earth’s gravity
- non-metal
-location is debatable
Alkaline Earth Metals
Be, Mg, Ca, Sr, Ba, Ra
- common O.S. = +2
- low densities, low melting and boiling points, low solubility, form basic oxides
Be: smaller, harder, higher melting point, higher ionization energy, more covalent bonding, less reactive than family members, amphoteric oxide
Mg, Ca: Biologically important! Lower solubility= hard water
Ba: Toxic, absorbs X-rays, not very soluble at low conc, useful tool for gastromedicine
Ra: Radioactive!
synthesis chemical rxns
A + B –> AB
decomposition chemical rxns
AB –> A + B
single re/displacement chemical rxns
AB+C –> AC + B
double re/displacement chemical rxns
AB + CD –> AD + CB
sodium metal and chlorine gas
synthesis: 2Na(s) + Cl2(g) –> 2NaCl (s)
magnesium metal and nitrogen gas
synthesis: 3Mg(s) + N2 (g) –> Mg3N2
Rubidium oxide and water
Synthesis: Rb2O (s) + H2O (l) –> 2RbOH(s)
Calcium metal and hydrogen (with heat)
synthesis: Ca(s) + H2 (g) –> CaH2 (s) (H- ion)
Magnesium nitride with water
Mg3N2(s) +6H2O (l) –> 3Mg(OH)2 + 2NH3
group 13
B, Al, Ga, In, Tl
Aluminum oxide (Al2O3 corundum structure) base for precious gems
B: not metal, supports 6 e- in valence, chem similar to Si
Ga: high density low melting point
Group 14
C, Si, Ge, Sn, Pb
common O.S. = +2, +4 (and -4, C and Si)
Can form 4 covalent bonds to nonmetals
C: form pi bonds, basis for life, allotropes: diamond, graphite, fullerenes
Si: Si-O bonds stronger than Si-Si bonds, basis for geological world
Ge: rare, semiconductor
Sn: soft metal, silvery color, allotropes: white, grey, brittle tin
Pb: soft, toxic, low melting point
Group 15
multiple O.S. states
N: Stable or highly reactive (N2 vs TNT) can form pi bonds, important for DNA, nitrogen fixation, atmospheric rxns
P: Larger, d-orbitals available for e- bonding, preseent in ATP, ADP, also important component of fertilizeer
As: toxic, semi-metal
Bi: Heavy, not toxic, substitute for Pb at times
Inert Pair Effect
When elements with several valence e- do not lose all of them, but keep 2 VEs in valence s orbital
Inert Pair cause and occurance
caused by: increasing ionization energies, related to size and effective nuclear charge (Zeff)
occurs: for heavier elements in p-block
Group 16
O, S, Se, Te, Po
common O.S.= 0 (O2), -1(peroxides), and -2 (MOST COMMON)
O: found in two molecular forms: O2 and O3(toxic)
S: unpleasant smell, chemical weapons, 30 solid allotropes,m s8 makes ring
Po: radioactive, lethal, present in tobacco
