According to Bohr's atomic model, valence electrons occupy specific energy levels or shells around the nucleus of an atom. These electrons are held in place by the electrostatic attraction between the positively charged nucleus and the negatively charged electrons.
In Bohr's model, valence electrons can transition between energy levels by absorbing or emitting energy in discrete amounts. However, the idea that a valence electron can escape from an atom solely due to being "not surrounded by anything else" or because of its small mass relative to a proton is not accurate within the context of Bohr's model.
The stability of an atom and the binding of its electrons are determined by various factors, including the balance of electrostatic forces within the atom. Valence electrons can be influenced by external factors such as the presence of other atoms or an external energy source. However, their ability to escape an atom depends on overcoming the attractive forces that hold them within the atom's electron cloud, rather than solely on the absence of surrounding electrons or their mass relative to protons.
It's important to note that Bohr's atomic model is a simplified representation and does not fully describe the behavior of electrons at the quantum mechanical level. A more accurate description of electron behavior is provided by quantum mechanics, which considers the wave-like nature of electrons and their probability distributions in atomic orbitals.