Any help would be good thanks

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a. the mitochondria b. the nucleus c. the vacuoles d. the endoplasmic reticulum

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as