问题 问答题

根据下列几种粒子的结构示意图,回答下列问题

(1)其中属于阴离子是______(填序号,下同);

(2)具有相似化学性质的是______;

(3)属于同种元素的是______.

答案

(1)粒子②核内质子数为8而核外电子数为2+8=10,核外电子数大于质子数,为阴离子;其它三种粒子的质子数均等于核外电子数,为原子;

(2)粒子①与③最外层电子数均为6,因此这两种粒子的化学性质相似,都能表现出得到2个电子的性质;

(3)粒子①与②核内均为8个质子,质子数相同,属于同种元素;

故答案为:(1)②;(2)①③;(3)①②.

阅读理解

If we find a bird nest (巢), we will have a good place of watching and knowing about birds. Birds sit on eggs and take care of their babies from April to June. Because the baby birds are too young to leave the nest, parents often go to look for food and come back in several minutes. So it is good to watch birds. When we watch birds, we'd better hide ourselves in a close place to the nest, and it's better to use binoculars (双筒望远镜).

But how do we make a bird nest? A good bird nest must be very fine, strong, thick and comfortable. If you want to make one, please follow these:

a) Each nest must have six boards (木板) for its cover and floor, for its left and right sides, and for its front and back sides. Don't make the boards too slippery (滑的).

b) Dig a small hole in the front of the nest as a "door". The "door" is big enough so birds can fly in or out easily.

c) Make sure the rainwater can't go into the nest.

d) One piece of the board should be easy to open.  

e) Don't forget to colour the nest.

小题1:We need ______ near a bird nest if we want to watch and know about birds.

A.a good place

B.some trees

C.to sit on eggs

D.to make a bird net小题2:When we're watching birds, we have to ______.

A.look after the birds more often

B.use the binoculars to catch the birds

C.hide ourselves to make the birds do everything as usual

D.catch the birds at last小题3:We should leave a hole in the front of the nest so that ______ easily.

A.we can clean the nest

B.birds can fly in or out

C.we can hang it

D.we can make it小题4:According to the text, we can make a bird nest like Picture ______ with the boards.

单项选择题