Olympiad Flashcards
What is the definition of allotrope?
What is an example of some allotropes?
Different forms of the same element (not isotopes)
Allotropes of carbon: (eg diamond, graphene, graphite).
What does none of the phosphorous in the body exist as?
None exist as elemental P.
What does tin exist as?
Different allotropes (as a metal though).
What do double salts contain?
How are they obtained by?
What is the water called and what is it incorporated into?
More than one cation or anion
Obtained by combination of two different salts which were crystallized in the same regular ionic lattice
The water is called water of crystallisation and is incorporated within the crystalline framework.
In chemistry, what does a dot mean between two atoms/molecules and what does this show?
Means chemically bonded. Used like punctuation to show the two separately but still bonded together.
In chemistry, what does a radical (or free radical) mean?
What might however free radicals be?
What are free radicals usually and why?
What can be formed under special circumstances and describe them?
A molecule that contains at least one unpaired electron
Although free radicals contain unpaired electron, they may be electrically neutral
Free radicals are usually highly reactive because of their odd electrons
Diradicals can be formed with unpaired electrons on each of two atoms (giving an overall even number of electrons), and these diradicals have a combining power of two.
What is a disproportionation reaction?
When something is simultaneously oxidised and reduced.
