Chapter 1 Flashcards
Why does atomic size increase when moving down a group on the periodic table?
Atomic size increases down a group because additional electron shells are added, increasing the distance between the nucleus and outer electrons. While the nuclear charge increases, the shielding effect from inner electrons reduces the attraction felt by the outermost electrons, allowing the atom to expand.
Why does atomic size decrease when moving left to right across a period?
Atomic size decreases across a period because, as protons are added to the nucleus, the nuclear charge increases. This stronger positive charge pulls the electrons closer, reducing the atomic radius. Despite the addition of electrons, they are added to the same energy level, increasing effective nuclear attraction.
How is ionization energy related to atomic size?
Ionization energy is inversely related to atomic size. As atomic size decreases, the electrons are closer to the nucleus and more tightly held, making it harder to remove an electron, resulting in higher ionization energy. Conversely, larger atoms have electrons farther from the nucleus, making them easier to remove and lowering ionization energy.
How are the reactivity of metals and reactivity of non-metals different?
The reactivity of metals and non-metals differs in how they interact with other elements. Metals tend to lose electrons easily, so their reactivity increases as you move down a group (larger atoms lose electrons more easily). Non-metals, on the other hand, tend to gain or share electrons, and their reactivity increases as you move up a group (smaller atoms attract electrons more easily).
How does the size of a cation compare to its parent atom?
A cation is smaller than its parent atom. When an atom loses an electron to form a cation, the loss reduces electron-electron repulsion and causes the remaining electrons to be pulled closer to the nucleus. This results in a smaller size compared to the neutral parent atom.
How does the size of an anion compare to its parent atom?
An anion is larger than its parent atom. When an atom gains an electron to form an anion, the added electron increases electron-electron repulsion, causing the electron cloud to expand. This results in a larger size compared to the neutral parent atom, as the increased repulsion pushes the electrons farther apart.
