lecture 7 Flashcards
what are the elements in group 2?
beryllium- Be magnesium- Mg calcium-Ca
strontium-Sr barium- Ba Radium-Ra
physical properties: atom size?
smaller than group A1
physical properties: atom size?
smaller than group A1
physical properties: melting point compared with group A1?
higher than group A1
physical properties: why are they a strong reagent?
because they readily lose valance electrons.
physical property that makes radium different.
all its isotopes are radio active
physical properties: divalent and ionic compounds:
are colorless.
physical properties: ionization energy compared to group A1
higher than group 1A
why is the ionization of A2 higher than A1?
because of the higher effective nuclear charge, and smaller size
physical properties: density compared to group A1
less dense than group A1
chemical properties: compared to group A1
less electropositive and less reactive but still reactive.
oxides of group 2A properties.
form basic solution.
melt at higher temperatures.
valance electron configuration.
ns^2
what is the element in group A2 that doesn’t behave like the rest of them.
beryllium
properties of beryllium.
steel gray, hard, high melting point, low density, high ressistance to corrosion, non-magnetic.
uses of beryllium
alloys to makes tough springs and non-sparking tools.
x-ray tube windows.
neutron source in nuclear reactor.
rockets and space craft
why is beryllium used in rockets and space crafts?
because of its light weight and strength
sources of beryllium?
bertrandite
beryl
bertrandite chemical formula
Be4S2O7(OH)2
beryl chemical formula and colors?
Be3Al2Si6O18
aquamarine
emerald
why causes the emerald color in beryl?
contaminated by Cr(III)
sources of magniesium?
common in sea water
mineral in nature