Final answer:
Electrons in energy level I, also known as energy level K, have the lowest energy and are closest to the nucleus. These innermost electrons are in the most stable position due to their proximity to the positively charged protons in the nucleus.
Step-by-step explanation:
The answer to the question about what characteristics electrons in energy level I (also referred to as energy level K) have is: B) The lowest energy and are closest to the nucleus. According to the atomic model and the concept of quantized energy levels, electrons that occupy the first energy level are closest to the nucleus of an atom and possess the lowest energy. Further, as electrons move to higher energy levels (labeled with an n value, such as n = 2, 3, 4, etc.), their energy increases. This increase in energy is necessary because negative electrons are attracted to the positive protons in the nucleus, making it necessary to add energy to move the electrons away from the nucleus.
Additionally, energy levels can be visualized as concentric circles around the nucleus, with valence electrons occupying the outermost energy level and core electrons occupying the inner levels. The energy levels are fixed distances from the nucleus, and electrons have specific energy states at these levels, not between them. Electrons in energy level I are therefore those that are at the lowest possible energy state in an atom's configuration.