For nonmetals, how does chemical reactivity trend in a period?
It increases across (left to right) a period.
It decreases across (left to right) a period.
It increases across (left to right) a period.
It increases across (left to right) a period.
The correct answer is that chemical reactivity generally decreases across a period for nonmetals.
Explanation:
To understand why this is the case, we need to look at the atomic structure and electron configuration of nonmetals. Nonmetals are located on the right-hand side of the periodic table.
As you move from left to right across a period, the number of protons in the nucleus increases, which means the positive charge in the nucleus also increases. At the same time, the number of energy levels or shells remains the same.
Now, let's consider the valence electrons, which are the outermost electrons in an atom. Nonmetals tend to have a high electronegativity, which means they have a strong attraction for electrons. As you move across a period, the number of valence electrons in nonmetals also increases. The increased pull from the growing number of protons in the nucleus makes it more difficult for nonmetals to gain additional electrons.
Because nonmetals have a strong desire to gain electrons to achieve a stable electron configuration, the ability of nonmetals to attract and gain electrons decreases across a period. Therefore, their chemical reactivity tends to decrease as you move from left to right across a period.
It is important to note that there are some exceptions to this trend, depending on specific elements and their unique electron configurations. However, as a general rule, nonmetals become less reactive across a period.