Periodic Table Flashcards
Factors affection ionisation energy
Nuclear charge
Atomic radius
Shielding
First ionisation energy
The energy needed to remove 1 mole of electrons from 1 mole of gaseous atoms
What happens as you move across periods
The ionisation energies are increased as there are more protons so pull towards the nucleus reducing the atomic radius
What happens as you descend the group
Ionisation energy decreases due to extra shells
Allotrope
Different forms of the same element in same state
Eg carbon- diamond graphite graphene
Metallic bonding
Metal cations electrostatically attracted to the delocalised negative electron. From lattice closely packed cations in sea of delocalised electrons
Simple molecular structure
Contain on a few atoms
Have covalent bonds between atoms
Strength of induced dipole dipole between molecules = how strong
Group 2 metals and water
From metal hydroxide and hydrogen
Group 2 and acid
Metal chloride and hydrogen
Sulfate Test
Add dilute HCl followed by BaCl2, if white ppt formed then sulfate
Why does ionisation energy drop between group 2 and 3
As group 3 is in p orbital rather than which has a higher energy
Shielding of S orbital
Exception between group 5 and 6
Group 5 electron is being removed from a singly occupied orbital while group 6 is from orbital containing 2 electrons
Repulsion between 2 electrons in orbital makes it easier to remove electron
Successive ionisation energy
Increase within each shell because electrons being removed from increasingly positive ion and less repulsion from remaining electrons
Diamond
Each carbon atom bonded to to 4 other High melting point Extremely hard Thermal conductor Doesn’t dissolve Doesn’t conduct electricity
Graphite
Weak forces between layers so can slide past each other
Delocalised electrons to carry current
Layers far apart so less dense than diamond, used in sports equipment
High melting point
Insoluble
Graphene
Delocalised electrons to carry electric current and also strengthen covalent bonds between atoms
Transparent and light
Metallic bonding
Outermost electrons are delocalised leaving a metal cation, metal cations are electrostatically attracted to delocalised electrons forming a lattice of packed cations in sea of delocalised electrons
Metallic bonding properties
number of delecalised electrons per atom affects the melting point
No bonds holding specific ions so is malleable and ductile
Delocalised electrons can pass KE
Simple molecular structure
Contain only a few atoms
Low melting and boiling points due to weak induced dipole forces
Noble gases exist as one atom so very low
Silver nitrate and chlorine
White ppt
Dissolves jn dilute NH3
Silver nitrate and Br-
Cream ppt
Dissolves in conc NH3
Silver nitrate and I-
Yellow ppt
Insoluble in conc NH3
Halogen disproportionation
Simultaneously oxidised and reduced when reacted with cold dilute alkali solutions
