How many protons are in an atom of copper? How many electrons are in an atom of copper? How many neutrons are in an atom of copper? Round your answer to the nearest whole number.
The Correct Answer and Explanation is:
Correct Answer:
- Protons: 29
- Electrons: 29
- Neutrons: 35 (for Copper-64, the most common isotope)
Explanation
Copper is a chemical element with the symbol Cu and atomic number 29. The atomic number tells us the number of protons in the nucleus of one atom of the element. Therefore, every atom of copper contains 29 protons.
In a neutral atom, the number of electrons is equal to the number of protons to balance the positive and negative charges. Since copper has 29 protons, a neutral copper atom also contains 29 electrons. These electrons are arranged in energy levels or shells around the nucleus. The distribution influences copper’s chemical behavior, especially in reactions where it forms ions such as Cu⁺ and Cu²⁺.
The number of neutrons in an atom is calculated by subtracting the atomic number from the mass number. Copper naturally exists primarily as two isotopes: copper-63 and copper-65. The average atomic mass of copper is approximately 63.55 atomic mass units (amu), which reflects a mixture of these two isotopes. However, for simplicity, we often round this to the nearest whole number and use copper-64 as a representative isotope in basic calculations.
To find the number of neutrons in a copper-64 atom, subtract the atomic number (29) from the mass number (64):
Neutrons = 64 – 29 = 35
So, a copper atom (specifically copper-64) contains 29 protons, 29 electrons, and 35 neutrons.
These subatomic particles each have important roles. Protons determine the identity of the element, electrons determine chemical behavior and bonding, and neutrons contribute to the mass and stability of the nucleus. Variations in neutron number give rise to different isotopes, which may have slightly different physical properties but the same chemical behavior.
