Toss the beef with 1/2 teaspoon each salt and pepper. Heat the oil in a pressure cooker over medium-high heat. Add the beef and cook, stirring occasionally, until browned on all sides, about 4 minutes.Add the onions and cook, stirring frequently, until the onions soften and begin to brown, about 4 minutes.eat the oil in a pressure cooker over medium-high heat. Add the beef and cook, stirring occasionally, until browned on all sides, about 4 minutes. Add the onions and cook, stirring frequently, until the onions soften and begin to brown, about 4 minutes.
Thus, metals have positive electron affinities. In the Periodic Table, electron affinity increases (becomes more negative) from left to right in a period. Electron affinity decreases from top to bottom in a Group.
electrons in a reaction. The electron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion. For example, when a neutral chlorine atom in the gaseous form picks up an electron to form a Cl-ion, it releases an energy of 349 kJ/mol or 3.6 eV/atom.It is said to have an electron affinity of -349 kJ/mol and this large number indicates that it forms a stable negative ion.lectron affinity: the energy change when a neutral atom attracts an electron to become a negative ion. Electronegativity: the ability of an atom in a molecule to draw bonding electrons to itself.