The rechargeable battery used in a mobile phone hand set is usually:

57 Element X reacts with element Y to form a compound Z. During the formation of compound Z, atoms of X lose one electron each whereas atoms of Y gain one electron each. Which of the following property is not shown by compound Z? 58 One of the following compounds is not ionic in nature. This compound is: 60 The number of protons in one atom of an element X is 8. What will be the number of electrons in its ion x^2-? 61 If the number of protons in one atom of an element Y is 20, then the number of electrons in its ion Y²⁺ will be: