EARTH SCIENCE (exam coverage)

• 840 million people lack primary access drinking water
• more than 800 children under age of 5 die from diearh cause by lack of water and sanitation everyday
• 2.3 billion people live without access to base sanitation
• 892 million ppl practice open defecation
• 98% of all natural disasters are water related
• oceans- largest Bodies of water
• sea- second to the ocean in terms of size
• lakes- created from various geological events
• oceans- 97% part of the earth
• Rivers and streams- flowing surface of water and its driven by gravity
• glacier's- Frozen and 68% pf fresh water can be found in here
• ground water -30 % of fresh water located here
• ground water- water that can be found in the rocks spaces and soil
• soil- Thin covering of earth surface
• soil content= 5% organic matter,45 % inorganic matter, 25% of water and 25% of air
• soil formation-combination of physical and chemical process
• soil texture -based on the proportion of sand ,salt,and clay sized
• soil texture - it influence the amount and movement of water that soil can hold
• soil texture - also tells how functional the soil is
• color- common physical property of soil that is noticeable
• color- use to indicating the chemical properties
• 3 primary pigments = black,red,and white
• Black - represent organic matter
• Red- rich in iron and aluminum oxides
• White -has silicates and salt
• Minerals - make up earth solid part and provide valuable sources
• scientists have identified 4000 different minerals
• small group of minerals make up almost 90% of the rocks of earth crust also known as forming minerals
• 5 requirements to substance to be fully minerals, Naturally occuring ,Inorganic,Solid,Definite chemical composition and ordered crystal structure
• Friedrich mohs- german geologist design the hardness scale also known as the mohs scale of hardness in 1892
• possible solutions to make:

  water conservation

  development of Groundwater

  Desalimination

  developing salt resistant crops

  improving integration of water use
• Soil - thin covering of the earth surface

  5% organic

  45% inorganic

  25% air

  25% water
• 5 common rocks → forming minerals

  alkali feldspars

  amphiboles

  calcite

  clay

  dolomite
• most abundant rocks - Alkali feldspar
• Study of minerals and their properties (chemical/physical)- Mineralogy
• A person who study of minerals - mineralogist
• physical and chemical properties of minerals:

  color

  crystal form/ habit

  hardness

  streak

  luster

  cleavage of fracture

  specific gravity's

  others( odor and taste etc)
• natural substance made of solid crystal of different minerals that have been fused together into solid lump - rocks
• 3 categories of rock

  igneous

  sedimentary

  metamorphic
• formed through Cooling and solidification of magma or lava = igneous rocks