Chemistry in the Lithosphere, Hydrosphere and Biosphere Topic 8

lithosphere

is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust

Lithosphere

It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below

core

is at the center of our planet and has a diameter of approximately 2500 km.

(Iron-Nickel alloy

solid in the inner core

iron

liquid in the outer core

mantle

thickness of 2900 km

4×10^ 24

mass of mantle

MAGNESIUM AND IRON

mantle compose mainly of

LOWER MANTLE

is predominantly formed by Mg-perovskite, Mg-wurstite, and Ca-perovskite , which contain water in their crystal structures. T

Mohorovicic Discontinuity

boundary between crust and mantle

gutenberg discontinuity

boundary between mantle and core

oceanic crust

It is only about 8 km beneath the ocean

continental crust

and an average of about 40 km under the continents

crust

is composed primarily of oxygenated compounds of Si (approximately 60%) and Al (approximately 15%): silica, quartz, silicates, silicoaluminates, and metal oxides

weathering

is the disintegration or alteration of crust minerals in their natural or original positions at or near the Earth’s surface through physical, chemical, and biological processes induced or modified by wind, water, and climate

temperature gradients

These gradients produce cracks in rocks as a result of expansion-contraction cycles

abrasion

Wind carries dust and solid particulate matter capable of abrading rocks and soils.

erosion

This condition, for example, can be brought about by water physically washing away soil particle

chemical weathering

When minerals are bathed with a film of water, many tend to dissolve. This process will depend on the solubility of the mineral or soil ions in water, and on the composition, pH, redox potential, and frequency of renewal of the aqueous film surrounding the mineral

biological weathering

Partially responsible for weathering phenomena are the biological processes that contribute to the emission of CO2 through respiration and photosynthesis, modifying the pH and alkalinity conditions in the surrounding water

97.5

percentage of salt water on earth

2.5

percentage of fresh water on earth

89.5

percentage of fresh water lakes

0.6

percentage of rivers

44

upper groundwater percentage

55.2

deep ground water percentage

evaporation

• Water from oceans, rivers, lakes, and other bodies of water is heated by the sun and changes into water vapor.

• Key Factors: Sunlight, temperature, and surface area

transpiration

• Plants release water vapor into the atmosphere through small pores in their leaves, called stomata.

• This process combines with evaporation

condensation

• Water vapor in the atmosphere cools and changes back into liquid droplets, forming clouds.

• Key Role: Responsible for cloud formation and occurs when air reaches its dew point (the temperature at which air becomes saturated with moisture).

precipitation

Water droplets in clouds combine and become heavy enough to fall to the Earth as rain, snow, sleet, or hail.

infiltration

Some of the precipitation seeps into the ground and becomes part of the soil or groundwater.

dissolve oxygen in water

It oxidizes organic and inorganic compounds present in water, allowing breakdown into basic nutrients

photosynthesis

• Equation: 6CO2+6H2O+sunlight→C6H12O6+6O26CO_2 + 6H_2O + sunlight \rightarrow C_6H_{12}O_6 + 6O_26CO2​+6H2​O+sunlight→C6​H12​O6​+6O2​

• Plants, algae, and some bacteria use sunlight to convert carbon dioxide and water into glucose and oxygen.

• Significance: Provides oxygen for respiration and organic compounds for food chains.

photosynthesis

energy source of biossphere

inorganic and organic compunds

electron source of biosphere

co2

carbon source of biosphere