10.1- THE HALOGENS Flashcards
Is the group 7 elements metals or non-metals?
non-metals
What do the group 7 elements exist as?
diatomic molecules
What is the group 7 elements called?
halogens
What is the appearance of the gaseous halogens?
vary in appearance
At room temperature what colour and state is fluorine?
pale yellow gas
At room temperature what colour and state is chlorine?
greenish gas
At room temperature what colour and state is bromine?
red-brown liquid
At room temperatue what colour and state is iodine?
black solid
Going down group 7 how does the colour and density of the elements change?
get darker and denser going down group
What smell does all the halogens have?
“swimming-bath” smell
What is a number of the properties of fluorine described as?
untypical
Where does many of the untypical properties of fluorine stem from?
F-F bond unexpectedly weak, compared with trend for rest of halogens
What is the size of fluorine like?
small size
What does the small size of fluorine lead to?
repulsion between non-bonding electrons as they’re so close together
How does electronegativity change going down group 7?
decreases going down group 7
How does atomic radius change going down group 7?
atomic radius increases going down group 7
How does melting point change going down group 7?
melting point increases going down group
How does boiling point change going down group 7?
boiling point increases going down group 7
Why does the atoms get bigger going down group 7?
because each element has one extra filled main level of electrons compared with one above it
What is electronegativity?
measure of ability of atom to attract electrons, or electron density, towards itself within a covalent bond
What does electronegativity depend on?
attraction between nucleus + bonding electrons in outer shell
What does the attraction between the nucleus + bonding electrons in the outer shell depend on? (3)
depends on balance between number of protons in nucleus (nuclear charge)
distance between nucleus and bonding electrons
shielding effect of inner shells of electrons
What happens to the shared electrons in hydrogen halides, HX going down the group?
get further away from nucleus as atoms get larger going down group
As the shared electrons get further away, what does this mean? (2)
shared electrons further from halogen nucleus + increases shielding by more inner shells of electrons
Which factors: shared electrons getting further from halogen nucleus + increased shielding OR increasing nuclear charge is more important?
shared electrons getting further from halogen nucleus + increased shielding
As the shared electrons getting further from the halogen nucleus + increased shielding are the more important factors, what does this mean? (hint-electronegativity)
electronegativity decreases going down group
Why does melting and boiling point increases going down the group?
as larger atoms have more electrons
As larger atoms have more electrons how does this affect VDW forces?
makes the van der Waals forces between molecules stronger
The lower the boiling point the more _____ the element?
the more volatile the element
