问题 填空题

如图中,A,B是碳元素和氮元素在元素周期表中的部分信息,C,D是两种粒子的结构示意图,仔细观察,按要求回答下列问题:

(1)氮元素的质子数是_______。

(2)若D粒子的化学符号为O2-,则x=_______。

(3)上述四种元素都属于_______(填“金属”或“非金属”)元素。

(4)请写出一种由上述任意三种元素组成化合物的化学式:_______。

答案

7    8   非金属元素    H2CO3或HNO3 

题目分析:(1)根据元素周期表中的一个小格提供的信息可知,元素符号前面的数字为原子序数,故氮元素的原子序数为7,在原子中,原子序数=核电荷数=质子数,故其质子数也是7。

(2)若D粒子的化学符号为O2-,说明该粒子带2个单位的负电荷,即其核外电子数比核内质子数多2个,再结合其粒子结构示意图,则有2+x-8=2,解得x=8。

(3)元素是具有相同核电荷数或质子数的同一类原子的总称,即核电荷数决定元素的种类,故C为氢元素,D为氧元素;而根据元素的汉字名称可判断元素的种类,由于以上4种元素的汉字名称要么带“石”字旁,要么带“气”字头,故都属于非金属元素。

(4)结合常见物质的组成分析,C、N、H、O四种元素中的任意三种元素,组成化合物的化学式可以是H2CO3或HNO3

点评:熟练掌握元素周期表的特点及其应用,以及原子核外电子的排布规律等,是解题的关键。

单项选择题

C

A scientist working at her lab bench and a six-old baby playing with his food might seem to have little in common.After all,the scientist is engaged in serious research to uncover the very nature of the physical world,and the baby is,well, just playing…right?Perhaps,but some developmental psychologists()have argued that this“play”is  more like a scientific investigation than one might think.

Take a closer look at the baby playing at the table.Each time the bowl of rice is pushed over the table edge,it

falls in the ground---and, in the process, it belongs out important evidence about how physical objects interact ; bowls of rice do not flood in mid-sit, but require support to remain stable. It is likely that babies are not born knowing the basic fact of the universe; nor are they ever clearly taught it. Instead, babies may form an understanding of object support through repeated experiments and then build on this knowledge to learn even more about how objects interact. Though their ranges and tools differ, the baby’s investigation and the scientist’s experiment appear to share the same aim(to learn about the natural world ), overall approach (gathering direct evidence from the world), and logic (are my observations what I expected?).

Some psychologists suggest that young children learn about more than just the physical world in this way---that they investigate human psychology and the rules of language  using similar means. For example, it may only be through repeated experiments, evidence gathering, and finally overturning a theory, that a baby will come to accept the idea that other people can have different views and desires from what he or she has, for example, unlike the child , Mommy actually doesn’t like Dove chocolate.

Viewing childhood development as a scientific investigation throws on how children learn ,but it also offers an inspiring look at science and scientists. Why do young children and scientists seem to be so much alike? Psychologists have suggested that science as an effort ---the desire to explore, explain, and understand our world---is simply something that comes from our babyhood. Perhaps evolution provided human babies with curiosity and a natural drive to explain their worlds, and adult scientists simply make use of the same drive that served them as children. The same cognitive systems that make young children feel good about feel good about figuring something out may have been adopted by adult scientists. As some psychologists put it, ”It is not that children are little scientists but that scientists are big children.”

According to some developmental psychologists,()

A. a baby’s play is nothing more than a game.

B. scientific research into babies; games is possible

C. the nature of babies’ play has been thoroughly investigated

D. a baby’s play is somehow similar to a scientist’s experiment

单项选择题 A1/A2型题