Final answer:
The statement is true because the atomic number of copper is 29, which matches the number of protons in the metal being described. The presence of 35 neutrons suggests the isotope copper-64, a less common isotope of copper.
Step-by-step explanation:
The statement that the metal with 29 protons and 35 neutrons is likely copper is true. The number of protons in an atom, also known as the atomic number, uniquely identifies an element. Copper has an atomic number of 29, which means every copper atom has 29 protons. An atom of copper with 35 neutrons would be the isotope copper-64 (29 protons + 35 neutrons = 64), which is a less common isotope of copper. The two stable isotopes of copper are copper-63 and copper-65, with atomic masses of approximately 63 and 65 atomic mass units (u) respectively.
When calculating the relative atomic mass of a sample that contains 69% copper-63 and 31% copper-65, this information can be combined to find an average mass. The calculation would be (0.69 × 63) + (0.31 × 65), leading to a relative atomic mass close to the standard atomic weight of copper, which is about 63.5 u.