Question

1. indicate whether the following properties increase or decrease from left to right of the periodic table.

a) atomic radius (exclude noble gases):
b) first ionization energy:
c) electronegativity:

Explanation:

• Atomic radius: As we move from left to right across a period (excluding noble gases), the number of protons in the nucleus increases. This leads to a greater positive charge in the nucleus, which pulls the electrons closer. So, the atomic radius decreases.
• First ionization energy: Ionization energy is the energy required to remove an electron from an atom. As we move from left to right across a period, the atomic radius decreases (as explained above). The out - er electrons are closer to the nucleus and more strongly attracted. So, it becomes more difficult to remove an electron, and the first ionization energy increases.
• Electronegativity: Electronegativity is the ability of an atom to attract electrons in a chemical bond. As we move from left to right across a period, the atomic radius decreases and the nuclear charge increases. This makes the atom more able to attract electrons, so electronegativity increases.

Answer:

a) Decrease
b) Increase
c) Increase