periodicity(everything from video Flashcards
dont do bad (18 cards)
where are metalloids located
along the staircase( starts with B then goes to Si)
-Periods row or column.
row(1-7)
what do all the elements in the same period have in common
contain same number of occupied energy levels
Group row or column
Column(1-14)
what do all the elements in the same group have in common
same number of valence electrons
chemical properties ver similar
what happens with atomic radius as you move down a group?
Why?
As you move down a group atomic radius increases.
Why: as the # of occupied energy levels increases so does the size of the atom
what happens with atomic radius as you move across a period
Why?(2 marks. state the same and the difference)
atomic radius decreases
Sam: all have same number of energy levels
Different: increasing number of protons as you move across causes greater attraction
why does ionic radius decrease when you go across a period( 2 marks)
same: number of protons
Different: extra electron more repulsion
how does amount of protons affect size
greater number of protons means smaller size
Ionization energy definition
- energy required to remove one electron from an atom in its gaseous state
Low value= easy to remove
what happens to ionization energy as you move down a group and why
Decreases
why: # of occupied energy levels increases, so the increased distance between the electron and the nucleus reduces attraction
what happens to ionization energy as you move across a period and why
Increases
Why- Same: same energy levels
Different: # of protons increase causing the nucleus to be more attracted to the energy level making it harder to remove
Definition of electronegativity
A measure of the ability to attract electrons in a covalent bond
- the higher the value the more strongly the atom wants to gain an electron
whats happens to electronegativity value as you move down a group.
Why?
decreases
Why: the bonding electrons are getting further from the nucleus and so there is reduced attraction
what happens to electronegativity value as you move across a period
why?
Increases:
Why: increase in protons resulting in increased attraction
Metallic oxides + H2O —>
Ph value?
Hydroxides
Ex: Na2O + H2O —> 2NaOH
greater than 7
nonmetallic oxides + H2O —>
Ph Value?
forms acids
Ph less then 7
metals vs non metals IB question
as you move across a period, oxides of the elements go from basic–> amphoteric–> acidic
