3-3.1 Classify rocks
(including igneous, sedimentary, and metamorphic) and soils (including humus,
clay, sand, and silt) on the basis of their properties. Taxonomy level: 2.3-B Understand Conceptual
Knowledge
Classify Rocks
It is essential for students
to know
that there are three classifications of rocks – igneous,
sedimentary, and
metamorphic. Rocks can be classified by properties, such as how they are
formed, color, visible
crystals or minerals, grain pieces, patterns in the rock such as stripes.
Igneous
· Igneous rock was once
melted but it has cooled and hardened.
· The melted material is
called magma or lava.
· Igneous rocks may be
glassy or grainy with crystals of different types of minerals in them.
· Granite is an example of
an igneous rock.
Sedimentary
· Sedimentary rocks are
usually made up of pieces of rock called sediments that have been
pressed and cemented together.
· Some may contain pieces
of animal shells or skeletons or other remains of plants or animals.
· Sandstone and limestone
are examples of sedimentary rocks.
Metamorphic
· Metamorphic rock was once
another type of rock deep inside Earth, but heat and the pressing
of the rocks above caused the minerals to
change.
· Rocks that were pressed
down could have the minerals line up in rows or bands.
· Sometimes the heat just
changes the size of the mineral crystals.
· Marble and slate are
examples of metamorphic rocks.
Classify Soils
It is essential for
students to know
that soil can be classified based on content, texture, or grain
size. Types of soil include
humus, sand, clay, and silt.
Sand
· Sand has large grains
with large spaces between the grains.
· This lets water leave it
quickly. Sand feels gritty.
Clay
· Clay has very small grains,
much smaller than sand or silt, and holds water easily.
· This makes clay sticky
when wet, but when it dries, it forms hard clumps.
Silt
· Silt has pieces that are
smaller than sand. It feels like powder.
Some soils are combinations
of these soil types. For example, “loam” soil has large and small
grains with lots of humus.
This makes it dark and rich soil for plants. Another example,
“potting soil” or “topsoil”;
also has a lot of humus. Once some sand has been added to it, it is
also good for growing
plants.
Assessment Guidelines: The objective of this
indicator is to classify types of rocks and soil; therefore, the primary
focus of assessment should be to group rocks and soils by the properties
used to describe them. However,
appropriate assessments should also require students to recognize a
particular rock or a soil type based on the description; exemplify rocks
that are classified as a particular type; or recall how a
particular rock type was formed.
3.3.2 Identify common
minerals on the basis of their properties by using minerals
identification key. Taxonomy level: 1.1-A, B Understand
Factual, and Conceptual Knowledge
It is essential for
students to know
that minerals are solid, formed in nature, have never been
alive, and have properties by
which they can be identified. Some examples of physical
properties of minerals may
be:
Hardness
· Hardness refers to
whether the mineral can be scratched or can scratch something else.
· The harder a mineral, the
fewer things can scratch it.
· The hardness is numbered
1-10 with 1 being the softest and 10 being the hardest. Diamond is
the hardest mineral.
Color
· Color can be used along
with other properties to help identify a mineral.
· Since many minerals have
the same color, it cannot be used as the only property for
identification.
Luster
· Some minerals can be very
shiny, pearly, or glassy and other minerals are dull.
Special Properties
· If an acid (vinegar) is
placed on a mineral, it may bubble or fizz.
· Some minerals split into
thin sheets. Some minerals have magnetic properties.
A mineral identification
key is a chart that will give information about the properties of the
minerals listed on the key.
Properties of a given mineral are compared to those listed on the key
and the mineral can be
identified. Some common minerals with very observable properties might
include calcite, feldspar,
mica, talc, gypsum, quartz, and fluorite. A sample mineral
identification key is
provided.
Assessment Guidelines:
The objective of this
indicator is to identify minerals based on their properties; therefore,
the
primary focus of assessment
should be to locate a mineral by its properties by using the
information found on an
identification key. However, appropriate assessments should also
require students to identify
mineral properties; or recall what would be observed when making an
identification of a
particular property.
3.3.3 Recognize types of
fossils (including molds, casts, and preserved parts of plants and
animals). Taxonomy level: 1.1-A Remember Factual
Knowledge
It is essential for
students to know
that a fossil is the remains of a living thing that lived long
ago that has turned to
rock. There are several types of fossils:
Mold
· A cavity or
opening in a rock that has the shape of once living thing.
· Fossil imprints of leaves
and other thin objects, such as wings, feathers, and footprints are
also molds.
· The leaves or animal
parts rotted away long ago.
Cast
· A mold that has been
filled in with sediments which harden and take the shape of the once
living thing.
Preserved parts
· Actual parts of the
living thing such as shells, bones, or teeth that have turned to stone.
· For example, sometimes an
insect long ago was trapped in tree sap.
· That sap hardened into a rock
called amber.
· The insect was preserved
in the amber stone.
Assessment Guidelines:
The objective of this
indicator is to recognize types of fossils; therefore, the primary focus
of
assessment should be to
locate a fossil type (including molds, casts, and preserved parts of plants
and animals) based on the
information presented about that fossil. However, appropriate
assessments should also
require students to identify a particular fossil from a drawing or
picture;
or recall types of
fossils as stated in the indicator.
3.3.4 Infer ideas about
Earth’s early environments from fossils of plants and animals that
lived long ago. Taxonomy level: 2.5-B Understand Conceptual
Knowledge
It is essential for
students to know
that fossils can give information about what the environment
was like in the location
where the fossil was found. For example,
· Fossils of a water
organism found in an area that is now mountains means that area was
possibly once under water.
· Fossils of trees or tree
parts that are found in a desert mean that area was possibly once a
forest.
· Fossils of plants that
are found in very cold areas of Earth means that area at one time
possibly had a warmer
climate.
Every time a new fossil is
found, more information about life on Earth and the environment of
Earth is discovered.
Assessment Guidelines:
The objective of this
indicator is to infer early Earth environments from fossil information;
therefore, the primary
focus of assessment should be to make a conclusion about the early
environment in an area on
the basis of the fossil organism. However, appropriate assessments
should also require
students to compare environments of early Earth with environments today;
or
exemplify organisms that might help
determine an environment.
3-3.5 Illustrate Earth’s
saltwater and freshwater features (including oceans, seas, rivers,
lakes, ponds, streams, and
glaciers). Taxonomy level: 2.2-A Understand Factual
Knowledge
It is essential for students
to know
that there are many places on Earth where water is found.
Sometimes the water is
saltwater and other times it is fresh water. Most of the water on Earth is
saltwater. Water is mostly
in liquid form in these features, but sometimes it can be solid (ice).
Earth’s water features
include:
Oceans
· Oceans are large bodies
of salt water that surrounds a continent.
Seas
· Seas are large bodies of
salt water that is often connected to an ocean.
· A sea may be partly or
completely surrounded by land.
Rivers
· Rivers are large, flowing
bodies of fresh water that usually empty into a sea or ocean.
Streams
· Streams are small,
flowing bodies of fresh water that flow into rivers.
Lakes& ponds
· Lakes and ponds are areas
where water, usually freshwater, are surrounded by land.
· Lakes and ponds differ in
size with ponds usually being smaller than lakes.
Glaciers
· Glaciers are huge sheets
of ice that cover land.
· They are found where
temperatures are very cold, for example, high in the mountains or near
the poles of Earth.
Assessment Guidelines:
The objective of this
indicator is to illustrate Earths saltwater and freshwater features;
therefore,
the primary focus of
assessment should be to give or use illustrations to show understanding of
Earth’s water features
(including oceans, seas, rivers, lakes, ponds, streams, and glaciers).
However, appropriate
assessments should also require students to identify oceans on a world
map; compare the
size of oceans, lakes, and ponds; or identify where glaciers might be
found.