Question

1. investigate: select h. in the gizmo, the hydrogen atom is shown next to a positive charge. as you move the atom to the right, the force of attraction between the positive charge and the valence electron will increase until the electron is removed. slowly drag the atom towards the charge. after the electron is removed, use the ruler to measure the distance between the original and the final position of the electron. record the distance and ionization energy in the table, then repeat for the other group 1 elements.

element h li na k rb cs fr
distance (no units)
ionization energy (kj/mol)

1. analyze: what trend do you notice?
2. investigate: gather data for ionization energy across a period. record in the table below.

element na mg al si p s cl ar
distance (no units)
ionization energy (kj/mol)

1. analyze: what trend do you notice?

Explanation:

Step1: Analyze group - 1 elements trend

As we move down group 1 (from H to Fr), the atomic radius increases. The out - ermost electron is further from the nucleus. So, the ionization energy decreases. The distance the electron has to move to be removed might increase as the atomic size increases.

Step2: Analyze period trend

Across a period (from Na to Ar), the nuclear charge increases while the shielding effect remains relatively constant. The atomic radius decreases. So, the ionization energy generally increases. The distance the electron has to move to be removed might decrease as the electrons are held more tightly.

Answer:

For group 1 elements: As we move down the group (from H to Fr), ionization energy decreases and the distance the electron moves to be removed might increase.
For period elements (from Na to Ar): As we move across the period, ionization energy increases and the distance the electron moves to be removed might decrease.