How do I find the number of energy levels in a positive and a negative ion? And also how do I find the number of electrons in a ion and a atom?

The question is too general because the energy levels flip flop at certain points; however, here are some guidelines for a specific elements.

For the second part first.
For oxygen:
Look at the atomic number. The AN is 8; therefore, it has 8 protons and that means 8 electrons for the neutral atom (all atoms are neutral). If it is O^2- then it must have two electrons extra or 10 electrons total.

For energy levels in Oxygen:
The electron configuration for
8O is 1s2 2s2 2p4.
The 1s2 represent 2 electrons in an s energy level (technically 2 energy levels; 1 for each electron) but most call the s level one energy level.
Then there is the 2s energy level and the 2p energy level. If you talk about the O^2- ion then add two electrons to it and you have 1s2 2s2 2p6.

To find the number of energy levels in a positive or negative ion, you need to understand the concept of electron configuration. Electron configuration refers to how electrons are arranged in the energy levels around an atom's nucleus.

1. Positive Ion:
When an atom loses one or more electrons, it becomes a positive ion (also called a cation). To determine the number of energy levels in a positive ion, you look at the electron configuration of the neutral atom it originated from.
- Find the atomic number of the neutral atom. This represents the number of protons and electrons in the atom.
- Subtract the number of electrons lost in the ionization process from the atomic number. The result will give you the number of electrons remaining in the ion.
- Utilize the periodic table or electron configuration charts to determine the energy level distribution of the remaining electrons. Each energy level can accommodate a specific number of electrons. For example, the first energy level can hold a maximum of 2 electrons, the second 8 electrons, and so on.

2. Negative Ion:
When an atom gains one or more electrons, it becomes a negative ion (also called an anion). To determine the number of energy levels in a negative ion, you follow a similar process as for positive ions.
- Find the atomic number of the neutral atom that the negative ion originated from.
- Add the number of electrons gained in the ionization process to the atomic number. The result will give you the total number of electrons in the ion.
- Use the periodic table or electron configuration charts to determine the energy level distribution of the electrons in the ion.

To find the number of electrons in an ion or an atom:
- For an ion, the number of electrons is determined by the charge on the ion. Positive ions have fewer electrons than their neutral atom counterparts, whereas negative ions have more electrons.
- For an atom, the number of electrons is equal to the atomic number of the element. The atomic number represents the number of protons and electrons in a neutral atom.

Remember, it's always helpful to consult the periodic table or electron configuration charts to determine the specific electron configuration and number of energy levels for a particular element or ion.