Question

1. investigate: choose electron affinity and select fluorine (f). in the gizmo, the fluorine atom is shown next to an electron. to measure the electron affinity, slowly drag the fluorine atom toward the electron. when the electron hops over, use the ruler to measure the distance. what is the ruler distance? what is the electron affinity? 11. explore: find the electron affinity for each of the other group 17 elements and each of the other period 2 elements. record these below. (note: if an atom has a positive ea it will have no attraction for an electron.) all values in the tables below will be in kj/mol. grp. 17 ea f: cl: br: i: at: ts: per. 2 ea li: be: b: c: n: o: f: ne: what is the trend in ea down a group? what is the trend in ea across a period? 12. think and discuss: what is the relationship between electron affinity and atomic radius? why do you think this relationship occurs?

Explanation:

Step1: Perform the Gizmo - based measurement

The ruler distance and electron - affinity values for fluorine in the Gizmo need to be measured by following the given procedure of dragging the atom towards the electron and using the ruler when the electron hops over. These values are experimental and can only be obtained by performing the action in the Gizmo.

Step2: Research electron - affinity values for Group 17 and Period 2 elements

For Group 17 elements (halogens):

• Fluorine (F): Electron - affinity values can be found from reliable chemistry data sources. The general trend down the group is that electron - affinity decreases. This is because as the atomic size increases down the group, the added electron is farther from the nucleus and experiences less attraction.
• Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At), Tennessine (Ts): Look up their electron - affinity values in chemistry textbooks or online databases.

For Period 2 elements:

• Lithium (Li), Beryllium (Be), Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), Neon (Ne): The general trend across a period is that electron - affinity generally increases (with some exceptions like nitrogen due to its half - filled p - orbital stability).

Step3: Determine trends

• Down a group: As mentioned, electron - affinity generally decreases because the atomic radius increases, and the incoming electron is less attracted to the nucleus.
• Across a period: Electron - affinity generally increases from left to right as the effective nuclear charge increases and the atomic radius decreases, making it more favorable for the atom to gain an electron.

Step4: Analyze the relationship between electron - affinity and atomic radius

Electron - affinity is inversely related to atomic radius. Smaller atoms have a greater electron - affinity because the added electron is closer to the positively charged nucleus and experiences a stronger electrostatic attraction. Larger atoms have a lower electron - affinity as the added electron is farther from the nucleus and is shielded by more inner - shell electrons.

Answer:

• Ruler distance (for F in Gizmo): Can only be determined by performing the Gizmo experiment.
• Electron - affinity (for F in Gizmo): Can only be determined by performing the Gizmo experiment.
• Grp. 17 EA: F: - 328 kJ/mol, Cl: - 349 kJ/mol, Br: - 325 kJ/mol, I: - 295 kJ/mol, At: - 270 kJ/mol, Ts: (estimated values as Ts is radioactive and data is limited).
• Per. 2 EA: Li: - 60 kJ/mol, Be: ~ 0 kJ/mol, B: - 27 kJ/mol, C: - 122 kJ/mol, N: - 7 kJ/mol, O: - 141 kJ/mol, F: - 328 kJ/mol, Ne: ~ 0 kJ/mol.
• Trend in EA down a group: Decreases.
• Trend in EA across a period: Generally increases.
• Relationship between EA and atomic radius: Inversely related. Smaller atomic radius leads to higher electron - affinity due to stronger electrostatic attraction between the added electron and the nucleus.