ES1 Flashcards
What is the lowest point on Earth?
The Dead Sea
How much salt is in the Dead Sea?
43 billion tonnes
What is the most reactive group of non-metals?
The Halogens
Are halogens found naturally in their elemental form?
No - found naturally in compounds
How abundant are the halogens?
- Cl and F are the most abundant
- Br in small quantities
- I is scarce
- At is artificially produced
What is the appearance of fluorine at room temperature?
pale yellow gas
What is the appearance of chlorine at room temperature?
green gas
What is the appearance of bromine at room temperature?
dark red volatile liquid
What is the appearance of iodine at room temperature?
shiny grey/black solid - sublimes to give purple vapour when heated
What are the trends of properties going down group 7?
- becomes darker in colour
- melting and boiling point increases
- changes from gases, to liquids to solids at room temp
- become less volatile
- reactivity decreases
Are the halogens more soluble in water or organic solvents?
organic solvents (e.g. cyclohexane and hexane)
What colour do the halogens give in water?
chlorine - pale green
bromine - orange/yellow
iodine - brown
What colour do the halogens give in cyclohexane?
chlorine - pale green
bromine - orange/brown/red
iodine - violet
Which elements are the strongest oxidising agents?
Elements at the top of the group
What are spectator ions?
Ions that are unchanged in an ionic reaction.
