Properties Flashcards
What do group 7 elements exist as ?
Diatomic molecules
What is meant by a diatomic molecule ?
When 2 atoms shake electron pairs in a covalent bond
What does fluorine exist as ?
A pale yellow gas
What does chlorine exist as ?
A green gas
What does bromine exists as ?
A red/brown liquid
What does iodine exist as ?
A grey solid
What happens on the atomic radius ?
The atomic radius increases down the group
What happens to electronegativity going down group 7?
As you go down group 7
Atomic radius increases and there is more shielding
So there is a weaker attraction between the nucleus and te shared electrons in a covalent bond
So electronegativity decreases
What happens to the boiling point of the halogens ?
The boiling point increases down group 7
Why does the boiling point increase down the halogen group ?
Because halogens are diatomic molecules and get larger down the group
Intermolecular forces such as the van der waals forces need to be broken to separate molecules during melting/ boiling
Van der waals forces get stronger as the number of electrons increases and molecular size increases
So more energy is needed to break the van der waals forces as they get stronger as atoms get larger
Which element has a higher boiling point ? Cl2 or F2 ?
Cl2 is larger than F2
So more van der waals forces and so Cl2 has a higher boiling point
What does the strength of the Evan der waals forces influence ?
It influences the booking point and therefore their state at room temp
