问题 填空题

(1)某元素的原子结构示意图为

,该元素原子核内有______个质子,核外共有______个电子层,最外电子层上有______个电子.

(2)用符号表示:2个氢原子______,1个钠离子______.

(3)“达菲”是应对流感暴发的储备药,莽草酸(化学式为C7H10O5)是合成它的主要原料.莽草酸的一个分子中共含有______个原子,其中氢、氧元素的质量比为______.

答案

(1)、由原子结构示意图的各部分的意义可知,圈内是质子数为16,核外共有 3个电子层,最外层上的电子数是6;

(2)、原子的表示方法就是用元素符号来表示一个原子,表示多个该原子,就在其元素符号前加上相应的数字,如:2个氢原子2H,;离子的表示方法:在表示该离子的元素符号右上角,标出该离子所带的正负电荷数,数字在前,正负符号在后,带1个电荷时,1要省略,如:1个钠离子Na+

(3)、由莽草酸的化学式为C7H10O5,则1个分子中含有7个C原子、10个H原子、5个O原子,原子总数为7+10+5=22;在C7H10O5,H、O元素的质量比为(1×10):(16×5)=1:8.

故答为:(1)16,3,6;(2)2H,Na+;(3)22,1:8.

阅读理解

阅读文章,选择正确答案。

    "Hi, Mommy, what are you doing?" asked Susie.

    "I'm making a dinner for Mrs Smith next door," said her mother.

    "Why?" asked Susie, who was only six years old."Because Mrs Smith lost her daughter and she has a broken

heart. We need to take care of her for a little while."

    "Why, Mommy?"

    "You see, Susie, when someone is sad, they have trouble doing the little things like making dinner. Because

Mrs Smith won't ever be able to talk with her daughter or hug her or do all those wonderful things that mommies

and daughters do together. Maybe you'll think of some way to help take care of Mrs Smith."

    Susie thought seriously about how she could do her part in caring for Mrs Smith. A few minutes later, Susie

knocked on her door. Mrs Smith answered the knock with"Hi, Susie." Mrs Smith looked as though she might

have been crying." What can I do for you, Susie?" asked Mrs Smith."My mommy says that you lost your

daughter and you're very very sad with a broken heart." Susie held her hand out. In it was a Band-Aid (创可贴).

"This is for your broken heart," Mrs Smith chocked back her tears. She knelt and hugged Susie. Through her

tears she said, "Thank you, darling girl, this will help a lot."

    Mrs Smith accepted Susie's kindness. She bought a small key ring with a picture frame (相框). She put

Susie's Band-Aid in the frame to remind herself to heal a little every time she sees it.

1. Mrs Smith is ________. [ ]

A. Susie's neighbor

B. Susie's aunt

C. Susie mother's friend

D. Susie mother's workmate

2. The reason that Mrs Smith has a broken heart is that ________. [ ]

A. she is in poor health

B. she is in trouble

C. she lost her daughter

D. her husband died in a traffic accident

3. Susie's mother _______. [ ]

A. often plays with Mrs Smith together

B. is busy with her work every day

C. is good at cooking

D. is kind to others

4. From Susie's sending Mrs Smith a Band-Aid, we can see ________. [ ]

A. Susie knows the real meaning"a broken heart"

B. Susie doesn't know what "a broken heart" mean

C. Susie often uses a Band-Aid in her daily life

D. Susie thinks Band-Aid can do anything

5. The best title for this passage is ________. [ ]

A. Fixing her broken heart

B. A kind girl

C. Susie and her mother

D. A good neighbor

单项选择题 A1型题