The number of electrons in an ion Y2+ is 10. The atomic number of element Y is most likely to be:

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The number of electrons in an ion Y²⁺ is 10. The atomic number of element Y is most likely to be:

as the symbol suggests the loss of two electrons, the atomic number is likely to be 12.

The cation of an element has:

Two elements X and Y have valencies of 5 and 3, and 3 and 2, respectively. The elements X and Y are most likely to be respectively:

A particle P has 18 electrons, 20 neutrons and 19 protons. This particle must be:

An ionic compound will be formed by the combination of one of the following pairs of elements. This pair of elements is: