Today we are going to make a bouncy ball. This experiment is best done by the sink.
What you will need:
Childsafe glue (PVAc)
Borax (be careful, borax is toxic and should not be eaten)
Cornstarch
A tap
Food coloring
A disposable chopstick (for stirring)
A cut-off plastic bottle or disposable plastic cup
A disposable soup spoon (for measuring - holds 20ml)
A cup (for holding the cornstarch)
▲ Put a spoonful of cornstarch into a cup.
▲ Put a spoonful of glue into the bottle. Wash the spoon with warm water. Dry the spoon.
▲ Add a drop of food coloring to the glue. Mix in well.
▲ Measure out an eighth of a spoonful of borax.
Carefully sprinkle the borax evenly over the surface of the glue. Don't stir it!
▲ Add the cornstarch on top of the glue and borax. Do not stir it.
▲ Count to 15.
▲ Using the chopstick, stir the mixture until it is all clinging to the chopstick.
▲ Remove the mixture from the bottle. Place it between your palms. Turn on the cold water tap and roll the mixture into a ball shape underneath the running tap.
▲ When the ball feels firm you can turn off the water. Wait a couple of minutes for the ball to dry out and then try bouncing it! Be careful where you leave your ball - others might mistake it for food. It musn't be eaten! If you want to keep your ball, store it in a ziplock bag.(CATHERINE THOMAS, STAFF WRITER)
今天我們要製作「彈跳球」，這個實驗最好在水槽裡面進行喔！
所需材料︰
兒童專用膠（白膠）
硼砂（請小心，硼砂具有毒性，千萬不要誤食）
玉米澱粉
水龍頭
食用色素
一根免洗筷（攪拌用）
切半的寶特瓶或免洗塑膠杯
免洗湯匙（測量用，容量二十毫升）
杯子（裝玉米澱粉用）
▲ 舀一匙玉米澱粉到杯中。
▲ 再裝一匙的白膠到瓶中。用溫水沖洗湯匙，然後擦乾。
▲ 滴一滴食用色素至白膠中，攪拌均勻。
▲ 準備八分之一匙的硼砂。仔細地將硼砂平均撒在白膠上，先不要攪拌！
▲ 再將玉米澱粉舖在上面，也先不要攪拌。
▲ 默數到十五。
▲ 開始用筷子攪拌，直到所有的東西都黏在筷子上為止。
▲ 將成品從瓶中取出，放在雙掌間。打開水龍頭的冷水，將混合物邊沖水邊搓成一個小球的形狀。
▲ 當小球質地變硬不再黏糊，就把水關起來。等待數分鐘讓小球完全乾了後，就可以測試它的彈跳力了。小心收好彈跳球，以免有人誤食！如果想保持球的彈性，可以把球收在夾鏈袋中。（翻譯：袁星塵）
What do you know about glue? What about the reaction between borax and glue? How about cornstarch? What kind of substance do you get if you mix water with cornstarch?
你對白膠了解多少？對白膠和硼砂間的反應作用又了解多少？玉米澱粉呢？若你將玉米澱粉和水混和，會得到什麼物質呢？
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