3. Objectives:
At the end of the lesson the student are
expected to:
a. name and differentiate the three chemical
layers of earth
b. cite the different characteristics of the 3
chemical layers of the earth
c. realize the way earth is designed to harbor
life

4. What are the four chemical
layers of the earth?

5.  Earth’s interior is composed of 4 layers:
3 solid and 1 liquid
1. Crust
2. Mantle
3. Outer core
4. Inner core

6.  Outermost layer – made of the lightest
materials - rock, soil & seabed.
 Divided into continental crust and oceanic
crust. Thickness ranges from 8km beneath
oceans to 40km beneath continents.
 Continents are relatively light ‘blocks’ floating
high on the upper mantle.
 Seafloor is made of ‘basalt,’ a denser rock that
presses deeper into the mantle.

8.  Upper mantle and lower mantle – 2900 km thick
(approx 84% of earth’s volume).
 Temperature ranges – 500ºC near crust to 4,000ºC
near outer core.
 Primarily solid, but the rock is so hot that parts of
the mantle ‘flow’ under pressure.
 Hot rock rises and cooler rock descends creating
slow moving currents.
 Composed of Magnesium, Iron, Aluminum, Silicon
and Oxygen.

9.  Liquid layer above the inner core – shell of
molten iron, 2,300 km thick.
 Cooler than outer core – but still scorching hot
at approx 4,500ºC .
 Mostly iron, plus sulfur & nickel.
 Electrically conducive liquid - Creates earth’s
magnetic field.

10.  Center of the earth - Deepest layer, 6250 km
under the surface
 A solid ball of an iron alloy (sulphur & nickle
traces).
 Solidified state due to intense pressure.
 2400 km in diameter, high pressure, WHITE
HOT like the sun - approx 6000ºC.

11. Write the correct answer of the following
question.
1-4 Name the four layers of the Earth in order, from
the outside to the center of the Earth.
5.What causes the mantle to "flow"?
6-10.Describe in your own words how the Earth's
harbors life.

12. Assignment
1.1.Bring a pre-cut styrofoam ball that resembles
the earth and bring styro or
posterpoint,newspaper and paintbrush.
2 2. Study about the Physical Layers of earth.

13. CENTRAL BICOL STATE UNIVERSITY OF
AGRICULTURE
PASACAO CAMPUS
STA.ROSA DEL NORTE, PASACAO CAMARINES
SUR
PREPARED BY:
ABEGAIL D. PATORITO
BSE-BIOSCI 3