Question

1. a student conducted an experiment with a chamber filled with nitrogen gas. during the experiment, a change in motion of the atoms of the nitrogen occurs as shown in the figure on the right.

what action by the student could have caused this change in atomic motion?
a. she spun the chamber in a centrifuge.
b. she placed the chamber in an ice bath.
c. she heated the chamber with a bunsen burner.
d. she added more nitrogen gas into the chamber.

1. molecules of oxygen are made of two oxygen atoms. when oxygen gas is cooled to $-183^circ$c, the gas becomes a liquid. draw a figure that models how molecules in a container of oxygen gas change when the gas becomes liquid.

oxygen molecules before cooling	oxygen molecules after cooling

Explanation:

1. For question 1: The figure shows nitrogen atoms moving slower and becoming more closely packed, which happens when a gas is cooled (loses thermal energy, reducing atomic motion). Heating would increase motion, centrifuging would only concentrate particles without slowing motion, and adding more gas would increase particle count but not change motion speed/packing this way.
2. For question 2: Oxygen gas has widely spaced, fast-moving O₂ molecules. When cooled to liquid, molecules lose energy, move much slower, and are tightly packed close together with little space between them.

Answer:

1. B. She placed the chamber in an ice bath.

2.

Oxygen Molecules Before Cooling	Oxygen Molecules After Cooling