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發表於 2005-7-11 08:35 PM
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Originally posted by tenmadio at 2005-02-01 07:07:
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1 _# g7 t4 ]& Eand thank you for asking  4 l3 n9 f) p5 F, \" O! J4 O
...
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here is a method to help you on your project...( y) p; A$ G) s+ E1 ^/ a; r
found this on internet
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. Y) D5 E( i. ~9 Y+ k4 S7 YDESCRIPTION : A chicken's egg is enclosed by a shell that has a high calcium content. If a raw egg (shell still intact) is placed in a glass of vinegar, a reaction (RXN) takes place. The acetic acid in the vinegar will dissolve the eggshell. The reaction will begin immediately when the egg is placed in the vinegar but will not be complete for two or three days. After two or three days, the egg will survive a drop of four to five inches. 4 K7 b* N7 ]9 ^6 j( e& s
BACKGROUND INFORMATION: This activity can be used to begin a lesson on states of matter. Be sure to completely cover the eggs with vinegar or hard shell will remain on those areas and quickly break the egg when it is dropped. Leave the eggs soaking in the vinegar for at least three days and be very gentle when removing them from the vinegar.
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. Q4 k! U4 m. {) ^1 ]' JGOAL: The students will observe the chemical reaction between calcium and vinegar. # F& t* G/ r# g+ H/ T! N/ _
# @( i6 f, S/ B: CCONCEPTS: Students will be able to: ( l, Q9 a& u0 h. y* \
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Set up and observe the chemical reaction between the calcium in a chicken egg to vinegar. 0 O1 r8 T) c" g2 w( u
" v$ F7 s7 I. ~; e! T. MTest the effects of the chemical reaction by having a bouncing egg contest to see which egg withheld the most bounces.
( B1 x" u% r8 s: m* _) P& uMATERIALS: 2 F7 _3 O. u4 h
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Raw chicken eggs
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Vinegar3 D/ `) X2 o2 Q& \$ l
, M( v- n7 N% M4 o) GPlastic spoon
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Clear plastic cups - p" \; u$ b! u, @- |$ O# a6 {
PROCEDURE: , A* w$ |' G$ n! w" w
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Allow each of the children to place a raw egg into a clear plastic cup (this is so that students can observe the chemical reaction on the entire egg)
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( f# W5 _6 ?0 t# b; a! X: s: FCompletely cover each of the eggs with vinegar ( it is very important to completely cover the entire shell!) ! a2 W) n# ^2 H8 F9 G! W
1 w0 Q( ~, O+ C7 @/ n) kSet the eggs in a place where they can easily be observed without needing to be moved for at least three days.
0 f# l# _/ Y* w3 a* J g2 n9 V fa) Have students carefully observe the chemical reaction on their egg.
% w) J& C$ Q* Xb) Keep a running journal on how much shell has disappeared.; Y1 k, }( A9 @+ p8 v0 K5 g( c
c) Have students write where the shell has gone and why they feel it disappeared.% V7 G1 y8 T3 |, f8 N$ w; k8 g7 w- Q" f
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VERY CAREFULLY remove the eggs with a plastic spoon.
+ h8 b# Q7 l7 w. p*There should be a thick waxy film on the egg.7 D8 j- {$ c, c/ Q4 Y5 W
# D0 P4 @% H5 b' n5 COne at a time, have students drop their egg ( about 4 to 5 inches) 9 r2 @8 m8 x7 W. a
a) Have entire class watch and record how many times each student's egg was dropped before breaking.
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* Bouncing Eggs: Amazing Science Activities You Can Do At Home, by William R. Wellnitz. i' x+ c9 `! R8 ]
http://www.amazon.com/exec/obido ... 102-3846259-0049733
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1 u, [3 J4 o9 s+ ^) }. a6 u1 w[ Last edited by tenmadio on 2005-7-11 at 07:36 AM ] |
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