8.2- TRENDS IN THE PROPERTIES OF ELEMETNS OF PERIOD 3 Flashcards
What does the Periodic Table reveal?
patterns in properties of elements
What is an example of periodicity in the Periodic Table?
every time you go across a period you for from metals on left to non-metals on right
What does periodic mean?
recurring regularly
What is periodicity explained by?
electron arrangement of elements
Are elements in group 1, 2 + 3 metals or non-metals?
metals
What sort of structure do elements in group 1, 2 + 3 have?
giant structures
What do elements in group 1, 2 + 3 do to form ionic compounds?
lose their outer electrons to form ionic compounds
How many electrons does silicon in group 4 have in its outer shell?
4 electrons
What does silicon do with its outer electrons?
forms four covalent bonds
What properties does silicon have?
has some metallic properties
What is silicon classed as, as it has some metallic properties?
semi-metal
Are the elements in group 5, 6 + 7 metals or non-metals?
non-metals
In regards to electrons, what do group 5, 6 + 7 elements do?
either accept electrons to form ionic compounds, or share their outer electrons to form covalent compounds
Why is argon unreactive?
its a noble gas in group 0- has full outer shell
What structures tend to have high melting + boiling points?
giant structures
Where are the elements with giant structures on the Periodic table?
on the left
What structures tend to have low melting + boiling points?
molecular or atomic structures
Where are the elements with molecular or atomic structures on the Periodic table?
on the right
Why does the melting + boiling points of metals increase from sodium to aluminium?
because of strength of metallic bonding
What happens to the charge on the ion as you go from left to right?
charge on ion increases
What happens as charge on ion increases as you go from left to right?
so more electrons join delocalised electron ‘sea’ that holds giant metallic lattice together
What does the melting point of non-metals with molecular structures depend on?
size of van der Waals forces between molecules
As the melting point of non-metals with molecular structures depend on size of VDW forces between molecules, what does this in turn depend on?
number of electrons in molecules + how closely the molecules can pack together
Why does silicon have a much higher melting point?
it has a giant structure
