4.11 - Trends in the Group 2 Elements Flashcards
Why are you unlikely to see a sample of radium?
Because all of its isotopes are radioactive
How can all of the other group 2 elements be described, when pure?
As bright silvery solids
What do the elements do when exposed to air?
React to form oxides as surface layers
What does this change about their appearance?
It makes them appear dull
What is the trend in the first and second ionisation energies as you move down the group?
They decrease in magnitude
What three factors have an impact on this trend?
The nuclear charge, orbital in which the electron exists, and shielding effect
What is the trend in nuclear charge?
It increases down the group
What does this mean for ionisation energies (just based on this factor)?
The ionisation energy increases, as the electron feels a stronger pull towards the nucleus, and this is what must be overcome
What is the trend concerning orbitals?
The energy the electron has increases, as higher orbitals have higher energy levels
What does this mean for ionisation energies (just based on this factor)?
The ionisation energy decreases, as the electron has more energy, and so is closer to being removed
What is the shielding effect?
The force of repulsion of a filled inner shell on the electron being removed
How does this effect increase in strength?
By the number of filled shells increasing
What does this mean for ionisation energies (just based on this factor)?
They decrease down the group, as the electrons are being repelled, and so less energy is required to fully remove them
