【简答题】(某白色固体可能含有氯化钠、硫酸钠、碳酸钠中的一种或几种,现将该固体溶于水配成溶液后,甲同学进行了验证实验,过程如下: (1)由甲同学的实验过程可知,该白色固体中含有 _________ .(填名称,下同)写出无色气体与澄清石灰水反应的化学方程式 _________ . (2)乙同学经过研究改换了上述实验中的①③两种试剂,除实验现象与甲同学的完全相同外,还将白色固体的成分确定了,则乙同学是把试剂①...
【单选题】将4gNaOH固体溶于水配成50mL溶液,其物质的量浓度为 ( )
【简答题】I would appreciate _____ it a secret. (A) your keeping (B) you to keep (C) that you keep (D) that you will keep
【单选题】Which of the following commands sets the secret password to Cisco?
A.
enable secret password Cisco
【简答题】A.private B.overt C.public D.secret
【多选题】若氢原子中的电子处于n=3的轨道,则它跃迁时()
【单选题】若氢原子中的电子处于n=3的轨道,则它跃迁时
【单选题】If you conceal a secret from your friends, you
B.
keep the secret hidden and don't tell it.
C.
hear them tell you the secret.