Click the answer you think is correct.

It may be helpful to work out the correct answer with a pencil and paper before first before clicking one of the choices provided.

For another question, select one of the options from the top of the menu on the left.

If you need help, select one of the options from the bottom of the menu.

You did not correctly indicate the number of times the first element appears.

Please use the information shown above to select the correct answer.

Congratulations! You have selected the correct answer.

For another question, select one of the options from the top of the menu on the left.

You did not correctly indicate the number of times the second element appears.

Please use the information shown above to select the correct answer.

You have the incorrect charge for the negative ion.

Please use the information shown above to select the correct answer.

You have the incorrect charge for the metal ion.

Please use the information shown above to select the correct answer.