# Exploring Creation with Physical Science Module 2 Study Guide

Humidity
the moisture content of air

Absolute Humidity
the mass of water vapor contained in a certain volume of air

Relative Humidity
the ratio of the mass of water vapor in the air at a given temperature to the maximum mass of water vapor the air could hold at that temperature, expressed as a percentage

Greenhouse Effect
the process by which certain gases (principally water vapor, carbon dioxide, and methane) trap heat that radiates from the earth

Parts Per Million (ppm)
the number of molecules (or atoms) of a substance in a mixture for every 1 million molecules (or atoms) in that mixture

The temperature is the same at 1:00pm on two consecutive days. For a person who is outside working, however, the second day feels cooler than the first day. On which day was the relative humidity the highest?
the first day; it wasn’t as humid on the second day because the relative humidity was lower than the first day.

A child decides to keep his goldfish in a small bowl. He has to add water every day to keep the bowl full. On two consecutive days, the temperatures are very similar, but on the first day the relative humidity is 90%, while on the second day it is 60%. On which day will the child add more water to the goldfish bowl?
the second day; the higher the relative humidity, the less the water will evaporate; the lower the relative humidity, the more the water will evaporate.

If you put a glass of water outside when the relative humidity is 100%, how quickly will the water evaporate?
not at all

Why does sweating cool people down?
When the humidity is low, your sweat evaporates, removing heat and cooling you down. It takes the energy from your skin.

What is the percentage of nitrogen in dry air? What about oxygen?
Nitrogen- 78%
Oxygen- 21%

What would be the consequence of removing all of the carbon dioxide in the earth’s air supply?
Plants would die (carbon dioxide is required for photosynthesis), and the earth would become much cooler because nothing would be absorbing the infrared light/heat (no more greenhouse effect).

What would be the consequence of removing all of the ozone in the earth’s air supply?
Ozone is destroyed by ultraviolet light, but in that process, the ultraviolet light is destroyed as well. If there were no ozone in the earth’s air supply, there would be a lot more ultraviolet light, which would harm living tissue even more than it already does.

What is the consequence of a sudden increase in the concentration of oxygen in the earth’s air supply?
1. Living things would be harmed. If the concentration of oxygen in the air exceeds 60% (it is currently 21%), then severe lung damage would take place. Blindness is a result of high concentrations of oxygen as well.
2. There would be a significantly greater risk of natural disaster by fire. The probability go a forest fire would increase 70% for every 1% rise in the oxygen concentration of the air.

Suppose astronomers found another solar system in which there was a sun just like our sun. Suppose further that a planet in this new solar system was just as far from its sun as is Earth from our sun. Since the vast majority of energy that plants get comes from their suns, is it reasonable to assume that the new planet would have roughly the same average temperature as that of Earth? Why or why not?
It is not reasonable to assume this. The atmosphere of this planet may be thicker, and the concentration of carbon dioxide might be either thinner or thicker than that of Earth- either trapping less or more heat. In other words, the greenhouse gases would most likely not be the same, therefore the planet would not have the same temperature as Earth’s.