Which of the following is a properly written formula for a compound between copper and bromine? cubr cubr cubr cubr

Elements are represented by their symbols with the first letter capitalized and the rest in lowercase. Copper is represented by Cu and Bromine is represented by Br. When combined to for a compound, the format of the symbols remain. Hence, the correct format would be CuBr. Thus, the answer is C: CuBr.

Copper, silver, aluminum, cobalt, chromium, mercury 

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom