GENERAL SCIENCE

• science is defined as a knowledge or system covering general truths or the operation of general laws especially as obtained and tested through scientific method
• hypothesis is an assumption or idea that is validated and tested through an experiment
• dependent variable is what you measure in the experiment and what is affected by the independent variables
• scientific law is a statement based on repeated experimental observation that describes some aspect of the world
• scientific theory is a tested nd widely accepted model that helps explain and predict natural facts and which is based on observations, experiments and reason
• model - aids in the visualization of occurrences and objects that cannot be observed directly
• the international system of units uses the seven base quantities and units
• Earth's Spheres:

  1. Lithosphere
  2. Hydrosphere
  3. Atmosphere
  4. Biosphere
• Lithosphere - solid, outer part of the earth
• Hydrosphere - total amount of water on a planet. includes water that is on the surface of the planet, underground, and in the air
• Atmosphere - is a layer or set of layers of gases surrounding a planet or other material body that is held in place by the gravity of that body
• Biosphere - the part of the world in which life can exist
• Igneous rocks - formed from the cooling of magma
• magma - very hot liquid found underneath the earth's surface
• Sedimentary rocks - formed from pre-existing rocks or pieces of once-living organisms
• Metamorphic rocks - formed through the alteration of pre-existing rocks in response to changing environmental conditions, such as variations in temperature, pressure, and mechanical stress, and the addition or subtraction of chemical components
• Weathering - breakdown of rocks at the earth's surface, by the action of rainwater, extremes of temperature, and biological activity
• Erosion - geological process in which earthen materials are worn away and transported by natural forces such as wind or water
• Lithification - process or processes by which unconsolidated materials are converted into coherent solid rock, as by compaction or cement
• Compaction - The process of compressing soil particles together to form a solid mass.
• Cementation - The process of binding sediments together with minerals that precipitate out of groundwater.
• Meteorology - concerned with the processes and phenomena of the atmosphere, especially as a means of forecasting the weather
• Weather - the state of the atmosphere with respect to the wind, temperature, cloudiness, moisture, pressure, etc.
• Climate - the long term (minimum 30 years) and average weather conditions for a specific region
• Gases found in the Earth's Atmosphere:

  1. Nitrogen - 78%
  2. Oxygen - 21%
  3. Other gases
• Layers of the Atmosphere:

  1. Troposphere
  2. Stratosphere
  3. Mesosphere
  4. Thermosphere
  5. Exosphere
• Troposphere - The lowest layer of the atmosphere, where weather occurs. It contains 75% of the atmosphere's mass.
• Stratosphere - The layer lies directly above the troposphere and is where the ozone layer is found.
• Mesosphere - a layer that is directly above the stratosphere and is 50-80 km above the Earth's surface. It is the coldest layer of the atmosphere where the temperature decreases with increasing altitude.
• Thermosphere - The layer of the atmosphere above the mesosphere and below the exosphere. (hot temperature)
• Exosphere - The outermost layer of the atmosphere. It is also the least known.
• Ecology - branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms
• Biotic - living things that affect the environment, such as plants, animals, and microorganisms
• Abiotic - non-living factors that affect the environment
• Population - The total number of organisms of a species in a particular area at a given time.
• Community - a group of populations of different species living in the same area.
• Ecosystem - The biological community of an area, including the abiotic factors and the interactions between the biotic factors
• Biome - area of the planet that can be classified according to the plants and animals that live in it
• Nebular theory - describes the formation of the solar system from a nebula cloud made from a collection of gas and dust. It is believed that the sun, planets, moons, and asteroids were formed around the same time 4.5 billion years ago from a nebula.
• Ptolemaic theory - the earth is the center of the universe and the sun, moon and planets orbit around it