皮皮学，免费搜题
登录
搜题
【简答题】
氢原子由一个质子和一个电子组成。根据经典模型，在正常状态下，电子绕核作圆周运动，轨道半径是r 0 = 5.29×10 -11 m。质子的质量M=1.67×10 -21 kg，电子的质量m=9.11×10 -31 kg，它们的电量为±e=1.60×10 -19 C。求电子所受库仑力是质子对它的万有引力的多少倍
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】简述Wilson病与Cp的关系。
【单选题】夜班护士,凌晨4:00采用臭氧灭菌灯对治疗室进行空气消毒30分钟,可进入治疗室的时间是( )
A.
4：35
B.
4：40
C.
5：00
D.
5：30
E.
6: 00
【单选题】夜班护士,凌晨4:00采用臭氧灭菌灯对治疗室进行空气清毒30 分钟,可进入治疗室的时间是:
A.
4:35
B.
4:40
C.
5 00
D.
5: 30
E.
6:00
【单选题】夜班护士,凌晨4:00采用臭氧灭菌灯对治疗室进行空气消毒30分钟,可进入治疗室的时间是
A.
4:35
B.
04:40
C.
05:00
D.
05:30
E.
06:00
【单选题】夜班护士,凌晨4:00采用臭氧灭菌灯对治疗室进行空气消毒30分钟,可进入治疗室的时间是
A.
04:35
B.
04:40
C.
05:00
D.
05:30
E.
06:00
【多选题】According to John Ikenberry, which of the following are historical cases of peaceful power transitions?
A.
the rise of Germany in the late nineteenth century
B.
the rise of the United States in early twentieth century
C.
the rise of Japan from the late 1940s to the early 1990s
D.
the rise of China in the twenty-first century
【多选题】Look at the sentences, and decide which are the historical factors influencing childhood they refer to.
A.
Today, children have few responsibilities, their lives are characterized by play not work, school not paid labor, family rather than public life and consumption instead of production.
B.
In contrast, children on the Pacific island of Tonga, studied by Helen Morton, are regularly beaten by their parents and older siblings. They are seen as being closer to mad people than adults because they lack the highly prized quality of social competence (or poto as the Tongans call it).
C.
Today, a four year old who can tie his or her shoes is impressive. In colonial times, four-year-old girls knitted stockings and mittens and could produce intricate embroidery: At age six they spun wool.
D.
While Westerners might take exception to eight-year-old girls working or to 12-year-old girls marrying, within their own communities such activities are seen as a normal and positive part of childhood.
【简答题】在T-SQL中使用【1】 语句声明变量;在引用全局变量时,必须以【2】 开头。
相关题目：