Periodicity Flashcards
What decides which element is in which block?
Depending on which orbital the highest energy electrons are in, (e.g. s-orbital, p-orbital, d-orbital).
What is a group?
The vertical column of elements.
What happens to the reactivity of s-block metals as you go do down the group?
They get more reactive as you go down.
What happens to the reactivity of p-block non metals as you go down the group?
They get less reactive as you go down.
What is a period?
Horizontal rows of elements are called periods.
What is periodicity explained by?
The electron arrangement of an element.
What type of elements are those that are in group 1, 2, 3
Metals
What structures do the elements in group 1, 2 and 3 have.
Giant structures
What properties does silicon have?
They have some metallic properties and is therefore classed as a semi-metal.
Why do the melting and boiling points increase from sodium to aluminium?
The metallic bonding strength increases due increased ion charges and the amount of electrons increase.
What do the melting points of non-metals depend on?
Intermolecular forces
What does the atomic radii tell us?
The size of atoms.
What is the atomic radius affected by?
The type of bond.
Why do nobles gases not get compared in atomic radii?
They cannot form covalent bonds.
Why can you not measure the radius of a lone atom?
There is no clear point where electron cloud density drops to 0.
When can metals form covalent bonds?
In a gas phase.
What happens to atomic radii across a period?
It decreases.
Why does the atomic radii change across a period?
The higher amount of proton charge has a stronger pull on electrons to the nucleus.
What happens to atomic radii down a group?
It increases.
Why does the atomic radii increase down a group?
The outer electron is further away.
What is the first ionization energy?
The energy needed to convert one mole of gaseous atoms into one mole of +1 positive charged gaseous ions.
What is the ionization equation?
M(g) -> M+(g) + e-(g)
or
M(g) + e- -> M+(g) + 2e-(g)
What happens to the first ionization energy down a group?
It decreases
What happens to the first ionization energy across a group?
Generally increases.
Why does the first ionization energy increase a group?
The amount of protons increases (stronger positive charge) but the electrons stays in the same level.
Why does the first ionization energy decrease down a group?
More inner levels means increased shielding so the outer electrons are easier to remove.
Why does oxygen have a lower ionization energy than nitrogen?
Nitrogen has half shell stability whereas oxygen doesn’t.
Why does boron have a lower ionization energy than beryllium?
Removing an electron from boron means it loses the p orbital.
Why does the successive ionization energy increase?
As you remove electrons the positive charge on the ion increases and the energy needed to remove an orbital is higher.
