Question

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?

1. 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?

1. explore: examine other groups and periods in the periodic table to see if the same trends exist. what trends do you see in ionization energy down a group and across a period?

Explanation:

Step1: Analyze group 1 elements trend

As we move down group 1 (from H to Fr), the atomic radius increases due to addition of electron - shells. The outermost electron is farther from the nucleus, so the ionization energy decreases. Also, the shielding effect of inner electrons increases, reducing the effective nuclear charge on the outermost electron.

Step2: Analyze period 3 elements trend

Across a period (from Na to Ar), the number of protons in the nucleus increases while the electrons are added to the same shell. The effective nuclear charge increases, pulling the electrons closer to the nucleus. So, the ionization energy generally increases across a period.

Answer:

1. For group 1 elements, as we move down the group, the ionization energy decreases and the distance of the outermost electron from the original position (when an electron is removed) likely increases (due to larger atomic size).
2. For period 3 elements, as we move across the period, the ionization energy generally increases and the distance of the outermost electron from the original position (when an electron is removed) likely decreases (due to increased effective nuclear charge pulling electrons in).
3. In general, down a group, ionization energy decreases because of increased atomic size and shielding effect. Across a period, ionization energy increases due to increased effective nuclear charge and smaller atomic size.