Cuprite, Cu2O, has a body-centered cubic unit cell of oxide anions with four copper cations in a tetrahedral arrangement around the body center oxide. Draw the unit cell in the empty cube. What is the coordination number and shape around the copper cations, and what is the charge on copper? Do the same analysis for the oxide anions.

The coordination number of Cu+ is two while the coordination number of O2- is 4

Explanation:

The coordination number of an ion in a unit cell arrangement refers to the number of immediate neighboring ions of opposite charge surrounding a particular ion. In Cu2O, the charge on Cu is +1 and the charge on the oxide ion is -2. Each copper I ion is surrounded by two oxide ions while each oxide ion is surrounded by four copper I ions in each unit cell.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.