periodic table Flashcards
what is ionisation energy
is the energy required to remove one electron from each atom in mole of gaseous 1+ ions.
what’s the first ionisation energy equation for na
na—-na+e-
what happens when an electrons lost from the highest energy level
it w experience the least attraction from the nucleus
what are three factors that affect ionisation energy
atomic radius-the greater the distance between the nucleus and the outer electrons the less the nuclear attraction.The force of attraction falls off sharply with increasing distance so atomic radius has a large effect.
nuclear charge-the more protons there are in the nucleus of an atom the greater the attraction between the nucleus and the outer electrons.
electron shielding-electrons are negatively charged and so inner-shell repulsion repel outer shell electrons.This repulsion is the attraction between nucleus and outer electrons
what’s mg’s second ionisation energy and what’s definition for sIE
mg+—mg2+ +. e-
The energy required to remove one electron from each ion in one mole of gaseous 1+ ions of An element to form one mole of 2+ ions
is the second ionisation energy greater than first
yes as after the first electron it becomes a + ion the second electron is pulled closer to the nucleus n held more tightly.The positive ion has less electron–electron repulsion.
The nucleus now has a stronger pull on the remaining electrons..The nuclear attraction on the remaining electron increasing and more ionisation energy needed to remove the second electron
What do successive ionisation energies provide evidence for
Different electron energy levels in an atom
On an ionisation energy chart for fluorine the spots higher up with a higher ionisation number have more ionisation energy why?
They are the ones closer to the nucleus and it changes from a n-2 to n-1 so the the large increase between 7 and 8 shows that the 8th electron must be removed from a diff shell closer to nucleus w less shielding
What do successive ionisation energies allow perfections to be made about
Number of electrons in outer shell
Group of element in periodic table
Identity of element
1-578
2-1817
3-2745
4-11577
5-14843
6-18389
Explain this ionisation chart
Huge inc between 3 and 4 shows 4th electrons being removed from an innner shell so there must be three electrons in the outer shell and the element must be in gotuo 3
What do periodic trends in first ionisation energy provide
Evidence for the existence of shells and subshells
What happens w first ionisation energy down a group
Decreases due to atomic radius increases so there more inner shells so shielding increases so nuclear attraction on outer electrons decreases.
What’s the trend in first ionisation energy across a period?
nuclear charge increases as no of protons inc. electrons added to same shell so there’s similar shielding, nuclear attraction increases causing atomic radius to decrease so first ionisation energy increases
In period 2 and 3 first ionisation energy falls in two places why?
Due to the existence of subshells, their energies and how programs fill with orbitals
Compare Beryllium and boron
The 2P subshell in boron has a higher energy than the 2s subshell in beryllium. So the 2P electron is easier to remove than one of the 2S electrons in beryllium. So the first ionisation energy in boron is less than first ionisation energy of beryllium
Compare nitrogen and oxygen
So there’s a fall from nitrogen to oxygen due to electron pairings in p orbital.
In nitrogen and oxygen highest energy electrons are in 2P subjsells
In oxygen the paired electrons in one of the 2P orbital’s repel each other making it easier to remove an electron from an oxygen atom than nitrogen.So ionisation energies of oxygen is less than nitrogen
In nitrogen there’s one electron in each box so equal repulsion as far as possible
In oxygen paired electronss repel
What’s a semi metal/metalloid
Elements near the metal/non metal divide that show inbetween properties
What metal isn’t a solid at rtp
Mercury
What’s metallic bonding and describe the structure
The strong electrostatic force of attraction between cations and delocalised electrons
Del electrons spread throughout whole structure as each atom has donated its vestige or electrons to shared pool of electrons. They are mobile throughout the whole structure. It surround cations which are fixed in position keeping structure and shape of metal. They are held together in a giant metallic lattice
Properties of metals
Strong metallic bonds-as there’s a great attraction between positive ions and delocalised electrons.
High electrical conductivity-delocalised electrons are mobile so they can carry charge throughout the structure due to DEL electrons moving towards positive terminal whilst negative terminal donates electrons that move into structure
High Mp +Bp-string metallic bonds holding together atoms on the giant metallic lattice and large amount of energy needed to overcome strong electrostatic attraction been cations and electrons.
inSoluble -only react they don’t dissolve
What’s a giant covalent structure
+ simple molecular structure
strong covalent bonds in a continuous network of atoms diamond, silicon dioxide, graphite
Molecules that form a simple molecular lattice structure held together by weak intermolecular forces-h20 n co2
What structure does carbon silicon and boron have and why
Giant covalent lattice -where many billions of atoms are held together by a network of strong covalent bonds to form a giant covalent lattice
Carbon and silicon are in group 4 of the periodic table and have 4 electrons in outer shells.They use these 4 electrons to form covalent bonds to other Carbon or silicon atoms. This results in a tetrahedral structure with a bond angle of 109.5.
diamond
Diamond has a giant covalent structure.
Each C atom forms 4 covalent bonds in a tetrahedral lattice.
Extremely hard, high mp and non-conductive.
Structure and bonding in diamon(carbon)
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