Earth Science (Chapter 17-20) Flashcards
Earth Science by Tarbuck, Lutgens, and Tasa (202 cards)
Ice is composed of water molecules that are held together by
mutual molecular attractions
the amount of heat required to raise the temperature of 1 gram of water 1°C
one calorie
Melting 1 gram of ice requires 80 calories, an amount referred to as
latent heat of melting
Freezing, the reverse process, releases these 80 calories per gram to the environment as
latent heat of fusion
Refers to the conversion of a solid directly to a gas, without passing through the liquid state.
Sublimation
the conversion of a vapor directly to a solid.
Deposition
other terms for frost
white frost or hoar frost
The general term for the amount of water vapor in air.
Humidity
A measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature.
Vapor Pressure
When air holds as much water vapor as it can for a given temperature (100% relative humidity), it is said to be
Saturated
If saturated air is warmed, it can hold _____ water (relative humidity drops), which is why warm air is used to dry objects–it absorbs moisture.
more
Refers to the mass of water vapor in a unit of air compared to the remaining mass of dry air.
mixing ratio
formula for mixing ratio
mixing ratio = mass of water vapor (grams) / mass of dry air (kilograms)
Ratio of the air’s actual water-vapor content compared with the amount of water vapor required for saturation at that temperature (and pressure). Thus, relative humidity indicates how near the air is to saturation rather than the actual quantity of water vapor in the air.
Relative Humidity
When the relative humidity reaches 100 per cent, the air is?
saturated
a decrease in temperature results in an _____ in relative humidity
increase
Refers to the temperature to which a parcel of air would need to be cooled to reach saturation.
dew-point temperature, or simply the dew point
Relative humidity is commonly measured using
hygrometer
One type of hygrometer, called a _________, con sists of two identical thermometers mounted side by side. One thermometer, the dry-bulb thermometer, gives the current air temperature. The other, called the wet-bulb thermometer, has a thin muslin wick tied around the end.
psychrometer
This drop in tempera ture occurs even though heat is neither added nor subtracted. Such variations are known as __________ changes and result when air is compressed or allowed to expand.
adiabatic temperature
When air is allowed to expand, it _______, and when it is compressed, it _____.
cools, warms
As it expands, it cools adiabatically. Unsaturated air cools at a constant rate of ________ of ascent
10°C for every 1000 meters
Unsaturated air cools at a constant rate of 10°C for every 1000 meters of ascent. Conversely, descending air comes under increasingly higher pressures, compresses, and is heated 10°C for every 1000 meters of descent. This rate of cooling or heating applies only to unsaturated air and is known as the?
dry adiabatic rate
The amount of latent heat released depends on the quantity of moisture present in the air, the wet adiabatic rate varies from 5°C per 1000 meters for air with a high moisture content to 9°C per 1000 meters for dry air. This slower rate of cooling caused by the addition of latent heat is called the?
wet adiabatic rate of cooling.