【单选题】Suppose that Sphere X had become unfastened from the floor of the vessel during Trials 1 and 7. During which of these trials would Sphere X more likely have undergone the lesser amount of acceleration...
A.
Trial 1, because the magnitude of the electrical force exerted by Sphere Y on Sphere X was greater in Trial 1 than in Trial 7.
B.
Trial 1, because the magnitude of the electrical force exerted by Sphere Y on Sphere X was less in Trial 1 than in Trial 7.
C.
Trial 7, because the magnitude of the electrical force exerted by Sphere Y on Sphere X was greater in Trial 7 than in Trial 1.
D.
Trial 7, because the magnitude of the electrical force exerted by Sphere Y on Sphere X was less in Trial 7 than in Trial 1.
【单选题】下列各物质的分类,名称(或俗称),化学式(或结构简式)对应错误的是()。
【单选题】氦是太阳 中含量较多的元素,其元素符号为 A . H B . He C . N D . O 28. 引起温室效应的主要物质是 A . SO 2 B . CO C . CO 2 D . 可吸入颗粒物 29. 属于氧化物的是 A . O 2 B . H 2 O 2 C . NaCl D . H 2...
【简答题】(12分)无机化合物可根据其组成和性质进行分类: (1)上述所示的物质分类方法名称是 。 (2)以Na、K、H、O、S、N中任两种或三种元素组成合适的物质,分别填在下表中②③⑥后面。(各空填写一个化学式即可) 物质类别 酸 碱 盐 氧化物 氢化物 化学式 ① HCl ② ③ ④Ba(OH) 2 ⑤Na 2 CO 3 ⑥ ⑦ CO 2 ⑧ Na 2 O ⑨ NH 3 ⑩H 2 O (3)写出⑦转化为...
【单选题】Suppose that all 6 genes are transferred from a donorbacterium to a recipient bacterium. Under this condi-tion, which student(s) would argue that Gene A couldbe the last gene transferred?
【单选题】下列化学式与其名称的对应关系正确的是
C.
纤维素[C 6 H 7 O 2 (OH) 3 ] n
D.
丙氨酸 CH 2 (NH 2 )CH 2 COOH