General Science

• Science - An organized body of knowledge gathered over a long period of time to explain the world

  we live in.
• 6 - how many scientific methods are there?
• Independent Variable – variable changed by the experimenter
• Dependent Variable – variable that responds to the variable that is changed in the experiment.
• Experimental group – groups that receive treatment.

  Control group – opposite of Experimental.
• hypothesis – it is what we think the answer to the question is and it should stated in terms of the variables defined.
• Scientific law – a description of a natural occurrence that has been observed many times.
• Scientific theory – a reasonable explanation of a scientific law. It is derived from a hypothesis that has been supported by repeated testing.
• Model – helps visualize occurrences and objects that cannot be observed directly.
• True or False: Scientific laws and theories cannot be proven absolutely. They are maintained as all observations support them.

  Answer: True
• Metric System - In science, the ________ is used in all measurements for its convenience and simplicity.
• 0.375 g - How many grams are there in 37.d centigrams?


  Explanation

  
• • Lithosphere – the solid part and the largest portion of the earth
  • Hydrosphere – the liquid part. It covers about 71% of the earth’s surface
  • Atmosphere – the gaseous portion that envelops the earth
  • Biosphere – the region where living things are found.
• What are the four major regions of the Earth?

  Lithosphere, Hydrosphere, Atmosphere, Biosphere
• Igneous rocks – these rocks are formed from hardened magma and lava.
• Sedimentary rocks – these rocks are form from deposited fragments or particles of other rocks that have been weathered and eroded.
• Metamorphic rocks – these are the rocks that have undergone changes due to heat and pressure
• Weathering - is a term for all processes which combine to cause the disintegration and chemical alteration of rocks at or near earth surface.
• Erosion - includes all the process of loosening, removal, and transportation which tend to wear away the earth’s surface.
• Lithification - is the conversion of unconsolidated sediment into solid rock.
• Meteorology – the study of the earth’s atmosphere, weather and climate.
• Weather – the daily condition of the earth’s atmosphere

  Climate – general conditions of temperature and precipitation in a large area over a long period of

  time.
• Oxygen and Nitrogen - the two gases that are mainly found in the atmosphere.
• Nitrogen

  • this gas in air reacts with chemicals to produce nitrates, which are used by living things for the manufacture of proteins
  • is returned to the atmosphere by the process of decay
• Oxygen

  • this gas is used for respiration
  • and for combustion process
• Layers in the atmosphere

  Troposphere – layer where life exists where different weather conditions prevail, it has the lowest temperature
• Layers in the atmosphere

  Stratosphere – contains ozone that serves as a protective shield against UV rays. Is where jetstreams is found
• Layers in the atmosphere

  Mesosphere – layer where meteoroids that enter the earth’s atmosphere are burned.
• Layers in the atmosphere

  Ionosphere – contains ions that are used for radio communications
• Layers in the atmosphere

  Exosphere – orbit space for artificial satellites.
• The uneven temperature and pressure in the atmosphere result in the movement of air called winds.
• Monsoons are examples of winds that result from the differences in the absorption and reflection of thermal energy by different materials of Earth.
• Ecology – the study of how living things interact with their environment.
• Ecological Factors

  1. biotic – all living factors in the environment

  b. abiotic – nonliving factors that are essential to living organisms
• Under Ecology

  • Population – a group of the same species living together
  • Community – all the different populations living together
  • Ecosystem – community of different living things interacting with one another and with their nonliving environment.
• Under Ecology

  Biomes – a large area whose ecological communities are determined by its climate.
• True or False: The age of a star is related to its temperature and its color.

  Answer: True
• Bluish and white stars are the hottest and youngest stars. The least hot and the oldest star are the reddish stars.
• Under Solar System

  Nebular theory – states that the solar system originated from a rotating gas and dust cloud composed of hydrogen, helium and some heavier elements.
• Under Solar System

  Ptolemaic Theory – The earth is stationary; each planet and the sun revolved around the earth.