f Giving reasons explain how the following periodic trends varies across and down the group (10 marks) Electron Affinity ii. Atomic radius iii. Electronegativity iv. Effective nuclear charge v. Ionization energy

Electron Affinity:<br />Electron affinity generally increases across a period from left to right and decreases down a group in the periodic table. This is because as we move across a period, the number of protons in the nucleus increases, leading to a stronger attraction between the nucleus and the added electron. As we move down a group, the added electron is placed in a higher energy level, which is farther from the nucleus, resulting in a weaker attraction.<br /><br />Atomic Radius:<br />The atomic radius generally decreases across a period from left to right and increases down a group in the periodic table. This is because as we move across a period, the number of protons in the nucleus increases, leading to a stronger pull on the electrons and a smaller atomic radius. As we move down a group, the number of energy levels increases, resulting in a larger atomic radius.<br /><br />Electronegativity:<br />Electronegativity generally increases across a period from left to right and decreases down a group in the periodic table. This is because as we move across a period, the number of protons in the nucleus increases, leading to a stronger attraction between the nucleus and the valence electrons. As we move down a group, the added electron is placed in a higher energy level, which is farther from the nucleus, resulting in a weaker attraction.<br /><br />Effective Nuclear Charge:<br />Effective nuclear charge generally increases across a period from left to right and decreases down a group in the periodic table. This is because as we move across a period, the number of protons in the nucleus increases, leading to a stronger attraction between the nucleus and the valence electrons. As we move down a group, the added electron is placed in a higher energy level, which is farther from the nucleus, resulting in a weaker attraction.<br /><br />Ionization Energy:<br />Ionization energy generally increases across a period from left to right and decreases down a group in the periodic table. This is because as we move across a period, the number of protons in the nucleus increases, leading to a stronger attraction between the nucleus and the valence electrons. As we move down a group, the added electron is placed in a higher energy level, which is farther from the nucleus, resulting in a weaker attraction.