A sample of copper has a relative atomic mass of 63.5. What are the relative abundances of the isotopes present in this copper sample?
- A25% $^{{63}}\text{Cu}$ and 75% $^{{65}}\text{Cu}$
- B50% $^{{63}}\text{Cu}$ and 50% $^{{65}}\text{Cu}$
- C75% $^{{63}}\text{Cu}$ and 25% $^{{65}}\text{Cu}$
- D90% $^{{63}}\text{Cu}$ and 10% $^{{65}}\text{Cu}$