问题 探究题

参与下面的探究。

情景一:夏天,小明为了解热,自己制作冰棒,当他将制好的冰棒连同冰棒模从冰箱内取出时,发现了一个奇怪的现象:原来与冰棒模口齐平的水结冰后,竟然向外“鼓”了出来,如下图1所示。

情景二:小红擅长用蜡塑像。可每次将熔化的蜡水倒进模型中冷却后,原来与模口齐平的蜡水中间却凹下却一个坑。如下图2所示。

问题:物质的温度降低后,体积增大还是缩小?

猜想:下面是三位同学对上述问题的看法及猜想。

甲:水结冰时膨胀了,表明物体温度降低时体积要增大。

乙:蜡水凝固时向内凹进,表明物体温度降低时体积要缩小。

丙:有的物质降温体积缩小,有的物体降温时体积增大。

实验:将水、食油、熔化的蜡烛、洗发精分别装满四个相同的小玻璃杯,放进冰箱的冷冻室内,待它们全部凝固后取出,观察体积的变化,结果发现:只有水结冰后表面向外鼓出来,其余液体降温后,表面都向内凹进。

(1)由小明和小红的经历,结合你自己的思考和经历,你更支持谁的看法?_______,理由是________________________________________________________。

(2)除了_________以外,一般的液体凝固后体积都要_____________。

(3)物质由液态变为固时,分子之间的距离要变______________。

(4)物质由固态变为液态或由液态变为气态时,体积要变_____________。

答案

(1)丙;一般液体变为固体,分子结合变得紧密,体积变小,而水发生反常膨胀。

(2)水;变小

(3)小

(4)大

选择题
阅读理解。

                                               Environment Awareness Week
Regal Convention Center, Halls 1-4
24-30 March 2011 10:00 am- 9:00 pm 
Free admission for all!
Save the environment, save our future
     Our environment needs help. With the participation of more than 50 organization, Environment
Awareness Week is the biggest public education event dedicated to environmental protection and
conversation. Don't miss it! Come and know more about:
The Threats to Earth(Hall 1)
     What is global warming? How serious is pollution? Learn about different environmental problems
from our university students. Protect our environment!
The Search for Renewable Energy(Hall 2)
      Can we get electricity from mind, solar energy, waves, rivers and underground heat? Get the
answers from Solar Ace, Teflou, TouchWind Resources and other participants.
The Quest for Freshwater (Hall 3)
     Is the shortage of freshwater worsening? What are Singapore's solutions for treating wastewater? Hear from Flow Technologies, HydroMax Solutions and other participants.
The 3 Rs to Save Earth(Hall 4)
     How can we REDUCE,REUSE and RECYCLE to cut down household wastes? Find out from
the Global Gaia work, Green Earth Foundation and other participants.
     For more information, please call Mr. Philip Koh at 6553 1188, send an email to Mrs Daisy Soh
at daisy-soh@ief.org or visit the event's web site at http://www.ief.org/eaw.
1. The main aim of Environment Awareness Week is to _____.
A. learn about renewable energy sources that protect the environment
B. explain ways for producing freshwater to save the environment
C. discuss global warming and other environmental problems
D. educate the public on protecting the environment
2. If you are interested in renewable energy sources, you should go to _____.
A. Hall 1
B. Hall 2
C. Hall 3
D. Hall 4
3. Which of the following statements is NOT true of the event? 
A. Each hall charges the same amount of money as the other.
B. You can send an email to Mrs. Daisy Soh for more information.
C. It will last a week and the halls will be open 11 hours a day.
D. Lectures in Hall 1 will be given by university students.
名词解释