【单选题】【消耗次数：1】
分子中存在着带正电荷的原子核和带负电荷的电子，整个分子呈现( ) 。
①
电性不一定
②
不带电
③
正电荷
④
负电荷
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相关题目
【多选题】
下列哪种蛋白质在pH值等于5.0的溶液中带正电荷
①
pI为4.5的蛋白质
②
pI为4.7的蛋白质
③
pI为7.0的蛋白质
④
pI为6.5的蛋白质E
⑤
pI为3.5的蛋白质
【单选题】
关于高斯定理，下列说法中正确的是（） （1）高斯面上的电场强度只与面内的电荷有关，与面外的电荷无关； （2）高斯面上的电场强度与面内和面外的电荷都有关系； （3）通过高斯面的电通量只与面内的电荷有关，与面外的电荷无关； （4）若正电荷在高斯面之内，则通过高斯面的电通量为正；若正电荷在高斯面之外，则通过高斯面的电通量为负。
①
（1）和（4）正确
②
（2）和（3）正确
③
（1）和（3）正确
④
（2）和（4）正确
【单选题】
俗话说“卤水点豆腐，一物降一物”，这其实说的就是胶体的聚沉。向胶体中加入酸、碱、盐，能使胶粒所带电荷被中和，从而“聚集长大”直至生成沉淀。实验证明，凝聚主要取决于胶粒带相反电荷的离子所带的电荷数，电荷数越大，凝聚能力越大，则向Fe(OH)3胶体中加入下列电解质时，其“聚沉值”最小的为(注：Fe(OH)3胶粒带正电荷）
①
NaOH
②
AgNO3
③
BaCl2
④
Na3PO4
随机题目
【单选题】
The old couple, whose kids have all passed away, have to ( ) only with their small pensions.
①
get at
②
get to
③
get by
④
get through
【单选题】
His handsome look, elegant taste, manners of gentleman, and ( ) knowledge in history and economy all intoxicated his pupils.
①
peculiar
②
profound
③
weird
④
abrupt
【单选题】
Bank of China has ( ) the other rivals by raising its offer.
①
trumped
②
attracted
③
won
④
judged
【单选题】
The leakage of the concrete ( ) of the contract between the two corporations has aroused much concern and a heated discussion in local residents.
①
portions
②
divisions
③
fragments
④
details
【单选题】
A ( ) is a second-year student in college, which means “student with more wisdom”.
①
freshman
②
sophomore
③
junior
④
senior
【单选题】
Initiative and spirit of ( ) are two key elements that ensure the rapid but steady progress of the corporation.
①
success
②
forgiveness
③
stealing
④
innovation
【单选题】
The young CEO lost his confidence and felt that hes an ( ).
①
deceiver
②
imposter
③
overseer
④
inferior
【单选题】
Earthquakes ( ) in the region about once a week, without the people feeling them.
①
struck
②
attacked
③
broke
④
occurred
【单选题】
After the break, the class resumed with ( ) spirit.
①
renewed
②
recurred
③
recalled
④
repayed