chemistry
posted by Nabiha .
Metals + cold water.
Li, Na, K, Ca.
Notes on reactions, equations or space? <<<< don't no what space or equations means. can someone help?
Also, say order of reactivity.

see equation 13.10 for these very active metal reactions.
http://books.google.com/books?id=rGM39e3HqvYC&pg=PA347&lpg=PA347&dq=active+metals++and+water+reactions&source=bl&ots=Q9PjQxytN0&sig=ApQu4us2xNoCfwa87sS1ludGmCE&hl=en&ei=TsO7SfviN4K2NPujlZYI&sa=X&oi=book_result&resnum=8&ct=result
I have no idea what space means here. Equations mean what is the reaction? 
Your cryptic question must be clarified if we are to help. Please amplify.

With Li, Na and K the reactions are exothermic [give out heat] and you would see flames and the metals would move vigorously on top of the water.
The reactivity order is Li<Na<K
so K is the most reactive.
The reaction of an alkali metal with water gives a Hydroxide and Hydrogen given off.
Here is the balanced equation for K
2K + 2H2O > 2KOH + H2
2Na + 2H2O > 2NaOH + H2
You can do the one for Li now.
For Ca the equation is slightly different as Ca has a valency of 2 so 2 OH ions can attach which gives
Ca+ 2H2O > Ca(OH)2 + H2
This reaction is less vigorous than the above metals [unless the water is hot in which case it's very vigorous]
I don't know what 'space' means for this question but I hope the rest has helped.