Investigating The Weather - 4th Grade Science Test - Thursday, October 27, 2011

Explanation
Data refers to raw facts, figures, or statistics that have no meaning or context on their own. On the other hand, information is processed and organized data that provides meaning and context. Therefore, the correct answer is "information" because it is the result of analyzing and interpreting data.

Explanation
A cloud is formed when water vapor in the air condenses into tiny water droplets or ice crystals. These droplets or crystals come together to form a visible collection of suspended moisture in the atmosphere, known as a cloud. Clouds can vary in size, shape, and altitude, and they play a crucial role in the Earth's weather and climate systems.

Explanation
Scientists classify clouds into three main types based on how and where they form. Clouds can form in three different ways: through convection, where warm air rises and cools, causing water vapor to condense and form clouds; through orographic lifting, where air is forced to rise over mountains or hills, leading to cloud formation; and through frontal lifting, where warm and cold air masses collide, causing the warm air to rise and form clouds. These three processes give rise to the three main types of clouds: cumulus, stratus, and cirrus.

Explanation
Cirrus clouds are thin and feathery clouds that form at high altitudes. They are composed of tiny ice particles and do not produce rain. When these clouds start to become puffy, it indicates the possibility of an approaching storm.

Explanation
Cumulus clouds are puffy white clouds that resemble cotton balls and are composed of tiny droplets of liquid water. These clouds are typically associated with fair weather. However, if they start to grow vertically and darken, it is an indication that a storm may be approaching.

Explanation
Stratus clouds are flat layers of clouds that resemble a blanket covering most of the sky. They are often the lowest clouds in the sky and can bring days of light, steady rain.

Explanation
A hurricane forms over warm ocean water because warm water provides the necessary energy and moisture for the development and intensification of tropical cyclones. As the water temperature increases, it increases the evaporation rate, leading to the formation of a large area of low pressure. This low pressure system, combined with the Earth's rotation, causes air to spiral inward, creating a rotating storm with strong winds. Therefore, the warmer the water, the more energy is available for the hurricane to strengthen and produce stronger winds.

Explanation
Thunderstorms usually form quickly due to the rapid heating of the air caused by huge sparks called lightning. This intense heating creates a disturbance in the atmosphere, resulting in the loud booming sound commonly associated with thunderstorms.

Explanation
A tornado is a rotating column of air that reaches toward the ground. It is formed from the most violent thunderstorms.

Explanation
The answer to the question is 109. This number represents the total count of tornadoes that occurred in Mississippi in the year 2008. It is stated that this number is a state record, indicating that it is the highest number of tornadoes ever recorded in Mississippi for a single year.

Explanation
A blizzard is a severe winter storm characterized by heavy snowfall, freezing temperatures, and strong winds. During a blizzard, the snow accumulates rapidly, making it difficult to travel and causing roads, cars, and buildings to be covered in snow. The combination of cold temperatures and strong winds creates blizzard conditions, which can be dangerous and often result in reduced visibility and extreme cold.

Explanation
Temperature describes how hot or cold something is. When the Sun's energy heats Earth's surface, the surface warms the air above it. The air temperature rises.

Explanation
The weight of air is called air pressure. Air pressure refers to the force exerted by the weight of the air molecules in the Earth's atmosphere. It is the measure of the force per unit area exerted on a surface by the weight of the air above it. Air pressure decreases with increasing altitude, as there are fewer air molecules above. It is an important factor in weather patterns and affects various aspects of our daily lives.

Explanation
Warm air weighs more than cool air because as air is heated, its molecules gain energy and move faster, causing them to spread out and take up more space. This increase in volume leads to a decrease in density, resulting in warm air being less dense than cool air. Therefore, warm air will weigh more than cool air due to its higher density.

Explanation
Moving air is called wind. Wind is the horizontal movement of air caused by differences in atmospheric pressure. It is created by the uneven heating of the Earth's surface by the sun, which causes air to rise and sink, creating areas of high and low pressure. As air moves from high pressure to low pressure, it creates wind. Wind plays a crucial role in weather patterns and can vary in speed and direction.

Explanation
Humidity is a measure of how much moisture is present in the air. In coastal areas and rain forests, where there is more water vapor, the humidity level would be higher. On the other hand, in desert regions where there is less moisture in the air, the humidity level would be low. Humidity is influenced by factors such as temperature, proximity to bodies of water, and precipitation levels.

Explanation
Precipitation refers to any form of water that falls from clouds, including rain, snow, sleet, and hail. It is the process by which water vapor in the atmosphere condenses and becomes heavy enough to fall back to the Earth's surface. Precipitation is an essential part of the Earth's water cycle and plays a crucial role in replenishing freshwater resources on land.

Explanation
An air mass refers to a large region of air that has consistent properties, such as temperature, humidity, and stability, throughout its extent. These air masses form and acquire their characteristics over specific source regions, which can be over land or water. As they move, they can influence the weather conditions in the areas they pass over, bringing changes in temperature, precipitation, and atmospheric stability. Therefore, an air mass is the correct term to describe a large region of air with uniform properties.

Explanation
A front causes a change in the weather. Fronts occur when two air masses with different temperatures and humidity levels meet. This collision creates a boundary between the two air masses, leading to changes in weather conditions such as temperature, precipitation, and wind patterns. Fronts can be associated with the formation of clouds, thunderstorms, and other weather phenomena.