问题 问答题

为了探究蜡烛燃烧的现象,做了下表中的实验,请你帮忙完成实验报告的内容:

实验步骤实验现象结 论
点燃蜡烛,将一根火柴横在火焰上方片刻;火柴梗的______(填“a”、“b”或“c”)处最先碳化.蜡烛火焰的______温度最高.
将一只干冷的烧杯罩在火焰上方;烧杯内壁出现水雾.说明蜡烛燃烧生成了______.
将一只内壁附有澄清石灰水的烧杯罩在火焰上方.烧杯内壁有白色固体生成说明蜡烛燃烧还生成______.

蜡烛燃烧的文字表达式为:

______.

答案

利用火焰外焰温度最高确定火柴梗的碳化位置,石蜡燃烧生成了二氧化碳与水,故将一个干冷的烧杯罩在火焰上方会看到有水雾生成,将一个内壁蘸有澄清石灰水的烧杯罩在火焰上方,会看到石灰水变浑浊.

所以实验报告的内容为:

实验步骤实验现象实验结论
点燃蜡烛,将一根火柴横放在火焰上方片刻火柴梗的a处最先碳化蜡烛火焰的外焰温度最高
将一个干冷的烧杯罩在火焰上方烧杯内壁出现水雾蜡烛燃烧生成水
将一个内壁蘸有澄清石灰水的烧杯罩在火焰上方烧杯内壁有白色固体生成蜡烛燃烧生成二氧化碳;

石蜡+氧气

点燃
水+氧气
故答案为:
实验步骤实验现象实验结论
a外焰
二氧化碳;

石蜡+氧气

点燃
水+氧气

阅读理解

A boy and his father were walking in the mountains. Suddenly the boy fell,hurt himself,and cried,"AAAhhhhhhhh!!!”  To his surprise,he heard the voice repeating(重复),somewhere in the mountain,“AAAhhhhhhhh!!!"Then the boy shouted,“Who are you?” He received the answer,"Who are you?" He got angry at the answer,so he shouted,"Foolish!" He received the answer,"Foolish!”

He looked at his father and asked,“What’s going on?" The father smiled and said,"My son,listen.”And then he shouted to the mountain,"1 love you!”The voice answered,“I love you!”Again the man cried,"You are the best!”The voice answered,“You are the best!”

The boy was surprised, but did not understand. Then the father explained(解释),"People call this‘Echo’,but really this is Life. It gives you back everything you say or do. Our life is just a reflection(反映)of what we have done. If you want more love in the world,have more love in your heart. If you want to be successful,work hard. This can be used in everything in life. Life will give you back everything you have given to it.”

小题1: At first the boy cried because _____ .

A.he hurt himself and felt bad

B.he wanted to give himself a surprise

C.he felt it was so quiet in the mountain

D.he hoped his father would help him小题2:When the boy heard the voice repeating, he thought ______ .

A.it was foolish to hear others’ voice

B.someone else in the mountain liked his voice

C.there were many other people in the mountain

D.he was laughed at by someone else in the mountain小题3: The father shouted to the mountain to ______ .

A.find out who was repeating his voice

B.have fun with other people in the mountain

C.show more examples to his son before giving him the answer

D.let his son know whose voice was louder小题4: The word "Echo" means _______.

A.life itself

B.repeating voice

C.love in the world

D.everything in life小题5: From the story,we know ______ .

A.the boy didn’t like others’ voice at all

B.the father had his own way to teach his son

C.it is not polite to repeat others’ voice

D.the boy and his father were rather tired

问答题 简答题