Period 3 Flashcards
What are the elements in period 3
Na
Mg
Al
Si
P
S
Cl
Ar
All elements of a particular perios have
The same number of shells
Non metallic character
Increases from left to right
Metallic character
Increases from right to left
How are cations (positve ions) formed
when atoms lose one more valence electron (usually the atoms are metals)
Reactivity of metals (cations)
Are based on how easily they lost electrons
Negative ions (Anions)
Are formed when atoms gain one or more valence electrons (these atoms tend to be non-metals)
What is the ease of ionisation
The energy needed for an atom to lose and electron (how easy it is to lose an electron)
As ease of ionisation increases
Reactivity increases (they have to lose to react)
Eg. Na becomes more reactive because it only has to lose 1 electron
What is reactivity
The energy needed for an atom to gain an electron
As reactivity increases
Reactivity increases. elements have to gain to react
Cl is more reactive because it only has to gain 1 electron
The metals from Na to Al that is going from left to right
The metals become less reactive as ease of ionisation increases. Na which has to lose only one electron is much easier to ionise compared to Mg which has to lose 2 because they have to lose to react
The metals from P to Cl
become more reactive as ease of ionisation increases because they have to gain to react
Atomic radius
Atomic radius decreases across a period as electrons are added to the same shell. The nuclear attraction increases as we go across as there are more protons in the nucleus. There is increased attraction between the nucleus and the valence electrons causing the atoms to contract from left to right.
Are metals reducing agents? why?
They ionise by losing electrons, therefore between sodium, magnesium and aluminium, sodium is the strongest reducing agent
