Sodium (Na) has a +1 charge and Iodine ( I ) has a -1 charge. To create a molecule of sodium iodide the charges will need to balance.
Because the charges on anion and cation are the same; the molecular formula will be NaI
What is the question you need answered
We have mass. Anything that generally includes atoms is matter
Chemical property of the substance but then again it could be physical
