Final answer:
The atomic radius increases down the periodic table and decreases across the periodic table. Electronegativity decreases down the periodic table and increases across the periodic table. First ionization energy increases across the periodic table and decreases down the periodic table.
Step-by-step explanation:
The trends in the periodic table can be summarized as follows:
- Atomic radius: The atomic radius generally increases down the periodic table and decreases across the periodic table. This is because as you move down a group, more energy levels are added, resulting in a larger atomic size. As you move across a period, the number of protons in the nucleus increases, causing the electrons to be pulled closer to the nucleus, resulting in a smaller atomic size.
- Electronegativity: The electronegativity generally decreases down the periodic table and increases across the periodic table. Electronegativity measures the tendency of an atom to attract electrons. As you move down a group, the atomic size increases, making the nucleus less effective in pulling bonding electrons. As you move across a period, the atomic size decreases, making the nucleus more effective in pulling the bonding electron pair to itself.
- First Ionization Energy: The first ionization energy generally increases across the periodic table and decreases down the periodic table. Ionization energy is the energy required to remove an electron from an atom. As you move across a period, the atomic size decreases and the effective nuclear charge increases, making it more difficult to remove an electron. As you move down a group, the atomic size increases, making it easier to remove an electron.