trends in the properties of the elements of a period on going from left to right?

As we move from left to right across a period in the periodic table, several trends in the properties of the elements can be observed:

1. Atomic Radius: The atomic radius decreases. This is because each element in a period has one more proton in its nucleus and one more electron in its outer shell than the element before it. The increased nuclear charge pulls the electrons closer to the nucleus, making the atom smaller.

2. Ionization Energy: The ionization energy increases. Ionization energy is the energy required to remove an electron from an atom. As the atomic radius decreases, the electrons are held more tightly to the nucleus and more energy is required to remove them.

3. Electronegativity: Electronegativity also increases. Electronegativity is a measure of the ability of an atom to attract electrons. As the nuclear charge increases, the atom is better able to attract electrons.

4. Metallic Character: The metallic character decreases. Metals are on the left side of the periodic table and nonmetals are on the right. As you move from left to right, the elements become less metallic and more nonmetallic.

5. Electron Affinity: Electron affinity generally increases across a period. Electron affinity is the energy change that occurs when an electron is added to a neutral atom. Atoms with greater electron affinities are more likely to gain electrons in chemical reactions.

These trends are useful in predicting the behavior of elements and in understanding their chemical properties.