The Group 7 Elements Flashcards
What are the group 7 elements?
Fluorine
Chlorine
Bromine
Iodine
Describe the uses of some Group 7 elements
- chlorine is used to sterilise water
- chlorine is used to make pesticides and plastics
- iodine is used to sterilise wounds
How do group 7 elements react with group 1 elements?
Vigorously
What happens to the reactivity of the group 7 elements?
The reactivity decreases as you go down the group
Describe the physical appearance of the group 7 elements at room temperature
- chlorine is a green gas
- bromine is an orange liquid
- iodine is a grey solid
Predict the properties of fluorine or astatine given the properties of the other group 7 elements. E.g.
- physical properties
- melting point
- boiling point
- displacement reactions
- high boiling point
- high melting point
- least reactive so can’t displace any of the other halogens from an aqueous solution of their metal halides
- has a density of about 7cm3
When does the metal halide form?
When a group 1 element reacts with a group 7 element
Describe the displacement reactions of group 7 elements with solutions of metal halides
- chlorine displaces bromides and iodides
- bromine displaces iodides
Explain why group 7 elements have similar properties, in terms of forming negative ions with stable economic structures
Because when the halogens react an atom gains one electron to form a negative ion with a stable electronic structure
Construct an equation to show the formation of a halide ion from a halogen molecule
F₂ 2e⁻ → 2F⁻
Cl₂ 2e⁻ →2Cl⁻
What is reduction?
The gain of electrons
Explain why a process is reduction from its ionic equation
By looking at its equation, if electrons are added then it’s a reduction reaction
Explain in terms of electron gain the trend in reactivity of the group 7 elements
The halogens have similar properties because when they react, an atom gains one electron to form a negative ion with a stable electronic structure
What are the group 7 elements known as?
The halogens
