25/2

i want to say something to ms jee before i start to blog...
i cannot use GOOD english to blog...because my english is not really good.= = but i still will try my best.

Today lesson, we learned about the purpose ,problems ,chemical reactions or physical changes.
All these we learned at secondary 4 already.But i felt that i need to start revise sec4 textbook ,because some parts all forgot= =

Then just now do the online monkey thing. 4 questions are balance equations. i completed 3 ,left 1 question still thinking...
?K2Cr2O7(aq) +? CH3CH2OH(aq) +? H2SO4(aq)->?Cr2(SO4)3(aq) + ?K2SO4(aq) + ?CH3COOH(aq) + ?H2O(1)

rah....i still cannot balance it.which part i do wrongly!!!!
ok. do chemistry worksheet first.Then ask people to help me this question= =
=)

24/2

chapter 3
Formulas to Names
-Memorized Names:
water - H2O
ammonia - NH3
methane - CH4
ethane - C2H6
propane - C3H8
-Systematic Names :
*You can recognize binary covalent compounds from their formulas, which contain symbols for only two, nonmetallic elements.
*The general :formulas is AaBb, “A” and “B” = nonmetals, and “a” and “b” = subscripts
*need to know all the prefixes and roots of the Nonmetals
-Ions:
*The positive cations and the negative anions then attract each other to form ionic bonds.
*The atoms of the noble gases found in nature are uncombined with other atoms.
chapter 4