The atomic number of oxygen is 8 because oxygen has?
8 protons in the nucleus.
electrons in 8 shells.
a second shell with 8 electrons.
an atomic mass of 8.
The correct answer and explanation is :
The correct answer is: 8 protons in the nucleus.
Explanation:
The atomic number of an element is determined by the number of protons in the nucleus of its atoms. For oxygen, its atomic number is 8, meaning it has 8 protons in the nucleus. The atomic number is a unique identifier for each element and determines its chemical properties, as well as its position in the periodic table.
Here’s a breakdown of how oxygen’s atomic structure works:
- Protons and Atomic Number:
The atomic number, which is 8 for oxygen, refers to the number of protons in the nucleus. Protons are positively charged particles, and the number of protons in the nucleus of an atom dictates which element the atom is. Since oxygen has 8 protons, it is classified as the element oxygen. - Electrons:
In a neutral oxygen atom, the number of electrons equals the number of protons, which is 8. Electrons are negatively charged particles that orbit the nucleus in specific energy levels or shells. The arrangement of electrons affects how atoms interact chemically with other atoms. - Electron Shells:
Oxygen has 8 electrons, and these electrons are distributed into different energy levels or shells. The first shell can hold up to 2 electrons, and the second shell can hold up to 8 electrons. Oxygen has 2 electrons in the first shell and 6 electrons in the second shell. This configuration explains why oxygen commonly forms two bonds to complete its outer shell, making it highly reactive. - Atomic Mass:
Oxygen’s atomic mass is approximately 16, not 8. Atomic mass is a weighted average of all the isotopes of an element, factoring in both protons and neutrons in the nucleus. The atomic mass of 16 comes from oxygen’s typical isotope, which has 8 protons and 8 neutrons. The atomic number (8) does not refer to the atomic mass but specifically the number of protons.
In summary, the atomic number of oxygen is 8 because it has 8 protons in its nucleus, which is the defining characteristic of the element oxygen.