What Makes an Atom of Gold so Special?
How many protons, neutrons, and electrons are there in an uncharged atom of gold?
An uncharged atom of gold has an atomic number of 79 and an atomic mass of 197. How many protons, neutrons, and electrons does it contain?
- 79 protons, 79 neutrons, and 118 electrons
- 118 protons, 79 neutrons, and 118 electrons
- 118 protons, 276 neutrons, and 79 electrons
- 79 protons, 276 neutrons, and 79 electrons
- 79 protons, 118 neutrons, and 179 electrons
Answer:
The atom has 79 protons, 79 electrons, and 118 neutrons.
Hi there! The atomic number of an element, in this case gold (Au), is equal to the number of protons it contains. For gold, the number of protons is 79. Since the atom is uncharged, the number of electrons it has is also equal to the number of protons, which is 79 as well.
The atomic mass of an atom is the sum of its protons and neutrons. The atomic mass of gold is 197, so by subtracting the number of protons from the atomic mass, we can find the number of neutrons. For gold, the calculation would be: 197 (atomic mass) - 79 (protons) = 118 neutrons.
Therefore, an uncharged atom of gold has 79 protons, 79 electrons, and 118 neutrons.