资料题:When its atoms leave their usual places, we say that an object is( )。
发布时间:2021-02-19
A.shrinking
B.expanding
C.changing places
D.melting
参考资料
Atoms are all around us.They are the bricks of which everything is made.Many millions of atoms are contained in just one grain of salt, but despite their small size they are very important.The way an everyday object behaves depends on what kinds of atoms are in it and how theyact.For instance, you know that most solid objects melt if they get hot enough.Why is this? It is the eat of the heat an the object's atoms.All atoms move constantly.When they are hot,they move faster.Usually the atoms in an object hold together and give the object is shape.But if the object grows hot, its atoms move so fast that they break the force that usually holds them together.They move out of their usual places 60 that the object loses its shape.Then we say that the abject is melting.
试卷相关题目
- 1An object holds is shape because its atoms( )。
A.usually hold together
B.move very fast
C.are very hot
D.are not moving
开始考试点击查看答案 - 2Atoms in an object move( )。
A.at all times
B.very fast
C.sometimes
D.unless the object has melted
开始考试点击查看答案 - 3The way an object behaves depends on the( )。
A.kinds of atoms in it
B.number of atoms in it
C.way its atoms behave
D.both A and C
开始考试点击查看答案 - 4One gain of salt contains( )。
A.a few thousand atoms
B.many millions of atoms
C.several heated atoms
D.one million atoms
开始考试点击查看答案