What is the period (left to right) trend in the first ionization energies? Why? It decreases because the nuclear charge decreases It decreases because the distance from the nucleus to the valence electrons decreases It increases because the nuclear charge increases It increases because the distance from the nucleus to the valence electrons increases

## Step 1: Identify the term "first ionization energy"The first ionization energy refers to the energy required to remove the most loosely bound electron from an atom in the gaseous state.## Step 2: Understand Periodic TrendsIn the periodic table, as you move from left to right across a period, there is a trend in the first ionization energies of the elements. ## Step 3: Identify the trendAs you move from left to right across a period, the atomic number of the elements increases. This means that the nucleus holds the electrons more tightly. Thus, you would expect that the first ionization energy will increase along a period.### The formula representing this trend is:**First ionization energy 1 / atomic radius** As we move from left to right, atomic radius decreases but nuclear charge increases, making it more difficult to remove the loosely bound electron. That's why ionization energy increases sequentially through a period.