Question

Whats the answer to this. me and my class are all stuck

Answer 1

The answer would be 8 electrons

As the element would want to complete its valence shell with "8 electrons", it will gain electrons hence attaining a negative charge

The "negative sign only" also shows that this element gained 1 electron so we can conclude that this element is in group VII A (Group 7 A elements gain 1 electron to complete their valence shell)

Answer 2

The iodide ion is denoted by the sign I-. This ion has a charge of -1, as indicated by the minus sign, which implies it has one more electron than the iodine atom (I), which is neutral.

Iodine (I), whose atomic number is 53, has 53 electrons in its neutral state. The iodide ion, which has a charge of -1, is created when an iodine atom gains one electron. The iodide ion (I-) therefore has 54 electrons :

53 electrons from the neutral iodine atom + 1 additional electron gained when it becomes an ion = 54 electrons in the iodide ion.

Всё легко и просто, удачи.