Why does F have a larger ionization energy that O?įluorine has a larger charge at its nucleus (Z eff ¬) than O, but the valence electrons in both atoms are approximately the same distance away from the nucleus. Thus the ionization energy for this process is positive.ġ0. Therefore, energy must be added in order to remove an electron from an atom. The negative electron is attracted to the positive nucleus. Less attraction equal lower ionization energy.Įlectrons are bound to an atom by electrostatic attractions to the nucleus. This increased distance means a decreased attraction between the nucleus and the outer electrons. This is because the outer electrons are further from the positively charged nucleus in a larger atom. Larger atoms generally have lower ionization energies. The elements are chemically active, dense, good conductors, solids at room temperature, and silver in color. Their valence shells are completely filled so they have no need or desire to lose or gain electrons.īa and Mg are alkaline earth metals located in group two. Noble gases are inert because they have the most stable electron configuration. They are both chemically reactive, have low densities, and gases or liquids at room temperature, and they both are often found in their +1 oxidation state. They are non-metals located in group seven.
Electronegativity decreases for this reason.Ĭl and Br are halogen elements. This means the outermost electrons get further and further away from the positively charged nucleus. As we navigate down a group the atoms get bigger and bigger with more and more electrons. As you move down a group, electronegativity decreases. When the valence shell of an atom is more than half full (like on the right side of the periodic table), it's easier to gain an electron. When the valence shell of an atom is less than half full (like on the left hand side of the periodic table), it's easier to lose an electron. Atoms can either gain electrons or lose electrons. As you move to the right across a period of elements, electronegativity increases. Atomic radii become larger as you go down a group because the outermost electrons are located in orbitals located further away from the nucleus (the principle quantum number, n, has increased).Įlectronegativity is a measure of the attraction an atom has for electrons. This increased charge pulls the electrons in closer. Atomic radii become smaller as you go from left to right across a period because the charge in the atom's nucleus becomes larger (increases Z eff). Electron affinity decreases as we proceed down a group for the same reason.Īn atomic radius is total distance from an atom's nucleus to the outermost electron orbital. This causes the electron to move closer to the nucleus, thus increasing the electron affinity. Moving from left to right across a period, atoms become smaller and smaller as the atomic number increases. This is caused by the decrease in atomic radius. Electron affinity increases from left to right across the periodic table. Ionization energy also decreases down a group for the same reason.Įlectron affinity is the amount of energy absorbed when an electron is added to an atom. It is harder to take an electron off a small atom, so ionization energy increases. Ionization energy increases across a period because as the number of protons increases the atomic radius decreases. Ionization energy is the energy it takes to remove an electron from an atom. Why does F have a larger ionization energy that O? Possible Answers
Why are ionization energies always positive?ġ0. What is the general relationship between the size of an atom and its ionization energy?ĩ. What is the group called and what number is it? Also name two properties that they would be expected to share.Ĩ. Barium and magnesium are both found in the same group in the periodic table. Are these elements metals or nonmetals? How many valence electrons do they have? Name a property that these two elements share.ħ. Chlorine and bromine are both found in the same group in the periodic table. What is electronegativity and what are its periodic trends?ĥ. What is an atomic radius and what are its periodic trends? Explain.Ĥ. What is electron affinity and what are its periodic trends?ģ. What is ionization energy and what are its periodic trends? Explain.Ģ.