(Green) Bonding I ionic Flashcards
(Green) Bonding I ionic
what is the definition of ionic bond
DEFINITION: An ionic bond is an electrostatic attraction between oppositely charged positive cations and negative anions. It is usually formed by electron transfer from a metal atom to a non metal.
Which group of elements will have the greatest tendency to lose their outer shell electrons?
Group I
Which is the second most likely group to lose outer shell electrons?
Explain why
Group II
Group I have a large atomic radius, outer electrons are readily lost, DHi(1) is low.
Group II have a fairly large atomic radius, outer electrons are readily lost, DHi(1+2) is fairly low.
One element in this second group does not in fact readily give up electrons. Identify this element and explain why it behaves differently.
Be – very small ionic radius, a Be2+ ion has a very high charge density and polarises the larger anion (pulls electron cloud towards itself and away from the anion) —-> a covalent bond.
Which group of elements will have the greatest tendency to gain outer shell electrons?
Group VII
Which is the second most likely group to gain outer shell electrons?
Explain why
Group VI
Fairly small atomic radius, if they gained one or two electrons they would be ISOELECTRONIC with a noble gas and stable.
info card (read and recite )
These oppositely charged ions are attracted to one another by strong electrostatic forces called ionic bonds. They form a giant ionic lattice where each ion becomes surrounded by a number of ions of the opposite charge.
What 2 factors does the co-ordination numbers in a lattice depend on?
- charge on the ions involved
- radius of the ions involved (actually the sum of the ionic radii)
what is the co-ordination number
it is the number of atoms that surround atom 1 : atom 2
Compare the sizes of atoms and the cations that they form. State and explain the difference.
Cations are smaller. Loss of electron(s) may result in loss of outer shell
Cation now has more positive protons than electrons so electrons will be attracted more.
Likewise compare the sizes of atoms and respective anions. State and explain this difference.
Anions are larger. Gain of electron(s) so e- > p+. electrons repel each other, held less strongly.
Why do the cations and anions increase in radius as a group is descended?
· More protons
· But more shielding by complete inner shells of electrons so less attraction of e-to p+.
· Another complete inner shell with successive periods
what does Isoelectronic ions mean
Isoelectronic ions are those having same electron configuration
what colour is Cu 2+
blue
what colour CrO4 2-
is yellow