What is the usual charge on an ion formed from an atom that originally had five valence electrons? a. 0 b. 3 c. -3 d. 5

c) -3

Explanation: The charge on an ion equals to the number of electrons an atom  gain or lose to get its nearest noble gas like electron configuration.

If an atom has 5 valence electrons then it would accept three electrons to complete 8 valence electrons in its valence shell.

8-5 = 3

Since, the atom has to accept 3 electrons, the usual charge on an ion formed will be -3.

(The charge is negative if the electrons are accepted and its positive if the electrons are lost.)

So, the correct choice is c) -3.

For example, N has 5 valence electrons, the usual charge on its ion is -3 as it accepts three electrons to complete its octet.(Neon like electron configuration).

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.