Group 7 Elements Flashcards
What is another name for group 7 elements?
The Halogens
What do group 7 elements all have in common?
They all have 7 electrons in their outermost shell
How does the molecular mass change as you go down group 7? Why?
Molecular mass increases as you go down group 7 as atoms get bigger.
How do the melting and boiling points change as you go down group 7?
The melting and boiling points both increase as you go down group 7
What is the colour and physical state of fluorine?
It is a yellow gas
What is the colour and physical state of chlorine?
It is a green gas
What is the colour and physical state of iodine?
It is a purple/black solid
What is the colour and physical state of bromine?
red-brown liquid
Describe the test for chlorine.
If damp blue litmus paper is placed in chlorine gas, it first turns red (acid) then bleaches white.
What is one common use of Group 7 elements?
They can kill microorganisms and remove the colour from materials.
Chlorine is commonly used in swimming pools and many types of bleach
How does the colour of group 7 elements change as you go down the group?
The colour gets darker as you go down group 7
Describe two ways that halogens are similar?
All halogens are toxic and corrosive. All have 7 electrons in their outer shell. All form diatomic molecules.
What is the trend in reactivity as you go down group 7?
Reactivity decreases
Explain the trend in reactivity as you go down group 7
Group 7 atoms gain one electron when they react.
Down the group, the distance between the outermost shell containing electrons and the positive nucleus increases.
This means that the force of attraction between the positive nucleus and an incoming negative electron decreases, and so it is harder to gain an electron and ions do not form so easily and the reactivity decreases.
What is the product when halogens react with metals?
Halogens react with metals forming ionic compounds (salts), which contain halide ions (X-) having gained one electron.
