What's right about the general properties of crystal? A: If there are anions in a crystal, there must be cations B: If there are anions in a crystal, there must be cations C: There are not necessarily chemical bonds in molecular crystals D: There must be no covalent bond in the ionic crystal

​An ionic crystal consists of cations and anions, therefore, the ionic crystal can conduct electricity.‍

Which of the following cations can be separated by NaOH solution? A: Cr3+ and Al3+ B: Cu2+ and Zn2+ C: Cr3+ and Fe3+ D: Cu2+ and Fe3+

For the differences of magnetic moments of the following cations in strong and weak octahedral crystal field, which difference is the smallest? A: Mn2+ B: Fe2+ C: Co2+ D: Cu2+

Which of the following properties have nothing to do with the dependence of the aqueous solution? A: The vapor pressure of the aqueous solution drops B: The freezing point of the aqueous solution decreases C: Different cations in aqueous solution show different colors D: The boiling point of the aqueous solution rises