In a laboratory activity the density of a sample of vanadium is determined to be 7.9g/cm^3 at room temperature. What is the percent error for the determined value?

What are the options? physical property can be color, smell, opacity, viscosity, density, infra red spectrum, melting and boiling points, attraction and repulson to magnets, etc.

Bromine has atomic number  35  which means there are  35 protons  and  44  neutrons to give a total of 79 nucleons. the fact that it's a positive ion means that it has lost an electron; so there'll be  34 electrons. 

The answer is january : )