1.1 Periodicity Flashcards
Covalent Radius
Half the distance between the nuclei of two atoms covalently bonded together.
State what is meant by the term first ionisation energy.
The energy required to remove on mole of electrons from one mole of gaseous atoms.
Explain why the first ionisation energy of the group 7 elements decreases going down the group.
More occupied shells so increased shielding.
Write the equation for the first ionisation energy of phosphorus.
Explain fully why the second ionisation energy is much greater than the first ionisation energy for group 1 elements.
Explain why the first ionisation energy of potassium is less than the first ionisation energy of lithium
Explain fully why the ionic radius of phosphorus is greater than the ionic radius of aluminium.
Explain the decrease in covalent radius going from nitrogen to fluorine.
Increasing nuclear charge
State the trend in electronegativity as you across period 2 from lithium to fluorine.
Increases across a period
Suggest why no values are provided for elements with atomic numbers 2,10 and 18.
They don’t form bonds
Explain why the electronegativity of the elements decreases as you go down the group.
Shielding increases so less of attraction of nucleus.
State what is meant by Electronegativity
The measure of attraction an atom has for the electrons in a bond.
Explain the decrease in atom size going across the third period from sodium to argon.
Explain fully the large increase between the first and second ionisation energies of sodium.
Second ionisation energy involves the removal of an electron from an electron shell that is closer to the nucleus. The second electron shell is less shielded.
Determine the enthalpy, in KJ mol ^-1
Na + (g) -> Na3+ + 2e^e
11472 (KJ mol ^-1)
