CMT Science Review: ANSWERS Grades 6-8

Content Standards 6.1-6.4

• Materials can be classified as pure substances or mixtures, depending on their chemical and physical properties

•An ecosystem is composed of all the populations that are living in a certain space & the physical factors with which they interact

•Water moving across & through earth materials carries with it the products of human activities

• Metals are this color on the table:• Non-metals are this color:• Semimetals (metalloids) are this color: Name two elements from each category!!

Periodic Table of the Elements

PINK

YELLOWGREEN

Calculating Density

Mercury is the only metal that is a liquid at room temperature. A scientist obtains a 20 ml sample of mercury. She determines the mass of that sample is 270.7 grams.

* What is the density of mercury?

DENSITY = Mass Volume

DENSITY = 270.7 g / 20 ml = 13.5 g/ml

Calculating Density, continued

Mrs. Lyver’s students find the mass of some zinc coins. Each coin has a mass of 21.4 grams. When placed in a graduated cylinder of water, each coin displaces 3 ml of water.

* What is the density of zinc?* What would be the density of 50 zinc coins? * If the coin is placed in a container of mercury, would it sink or float?

DENSITY = Mass Volume = 21.4 g / 3 ml = 7.1 g/ml

Same!! Zinc is zinc, no matter how much there is!

Float!

Soil is made of minerals, organic matter, air and water.

Chemically, soil is considered to be a _____________.

List at least 4 facts about soil:1.2.3.4. Find more facts here!!

MIXTURE

The Soil Ecosystem

Identify examples of producers & consumers that are typically found in a soil food web

See a food web here!

Need help??

A student carries out an experiment

to determine if soil composition

affects its absorbency.

Study the data table on the following slide

and respond to the corresponding

questions…

SOIL TYPE Amount of Water IN

Amount of Water OUT

1. SAND 100 98

2. TOPSOIL 100 85

3. TOPSOIL + CLAY 100 60

4. TOPSOIL + CLAY + POTTING SOIL

100 40

* What errors did the student make when placing data into the data table?

* What scientific question do you think the student was trying to answer?

NO Title or Units or Multiple Trials, etc.

(Hint: It should be very similar to the problem on previous slide!) “What effect will soil composition have on water absorbency?”

Content Standard 6.4a

• Most precipitation that falls on Connecticut eventually reaches Long Island Sound

WATERSHED

Protecting our watersheds from “point” & “non-point” pollution

Take a look at the “Stop Pointless Per sonal Pollution”

bulletin (first link under “grades 6-8”) and then complete the table below!

Habits that can harm the LIS watershed

Things that we can do to help prevent pollution!

1.

2.

3.

For each of the photos in the following

slides try to determine:

1. The specific role that the organism plays in the ecosystem.

2. How the organism obtains the energy it needs to live.

3. Another organism that depends on that one for survival.

4. Three specific abiotic factors that this organism requires for survival.

Example: Role: Herbivore, primary consumer

Obtains energy by: eating plant matter such as acorns, fruits, small saplings of deciduous trees, leaves of certain shrubs, mushrooms, tree buds, and wildflowers

Another organism that depends on it: Parasites such as the deer tickThree specific abiotic factors it needs: oxygen, water, proteins

White tail deer

Role:

Obtains energy by:

Another organism that depends on it:

Three specific abiotic factors it needs:

White Oak

Your Turn!!

Example:Role: Producer

Obtains energy by: Using the sun for photosynthesisAnother organism that depends on it: Any animal that eats acorns or leaves or saplings (ex: deer)

Three specific abiotic factors it needs: Carbon dioxide, sunlight, minerals such as nitrogen

White Oak

Your Turn!! Role:

Obtains energy by:

Another organism that depends on it:

Three specific abiotic factors it needs: Red Tailed

Hawk

Example: Role: Top level consumerObtains energy by: eating other, low level consumers such as rabbits & pigeonsAnother organism that depends on it: Parasites like fleas & ticks; Great horned owls & crows prey on the hawk’s eggs and chicksThree specific abiotic factors it needs:

oxygen, nutrients such as proteins and fats

Red Tailed Hawk

Role:

Obtains energy by:

Another organism that depends on it:

Three specific abiotic factors it needs: Asian Tiger Mosquito

Your Turn!!

Example: Role: Top level consumer (parasite)

Obtains energy by: sucking blood from other animals

Another organism that depends on it: Bats, birds, and some types of fish eat mosquitoes

Three specific abiotic factors it needs: water, warm air temperatures, nutrients such as protein

Asian Tiger Mosquito

Role:

Obtains energy by:

Another organism that depends on it:

Three specific abiotic factors it needs:

Puffball mushrooms

Your Turn!!

Example: Role: Decomposer

Obtains energy by: breaking down organic matter in the soil and absorbing the nutrients

Another organism that depends on it: Certain insects, turtles, & rodents will eat mushrooms; deer will too!

Three specific abiotic factors it needs: Darkness, cool temperatures, moisture

Puffball mushrooms

Extension Activity:

Build a food chain that includes

at least one of the organisms shown in the previous slides.

Play a food chain

game!

1. Mushroom Deer mosquito

2. Acorn Squirrel coyote tick

3. Oak sapling Deer coyote

Examples:

Content Standard 6.3

• Local & regional weather are affected by the amount of solar energy the area receives and proximity to a large body of water

Defend the following statement:

“The sun is the main source of energy on earth”

Remember that you should always support

your views with evidence!

The sun provides light energy which can be absorbed &

converted to other forms of energy…like thermal, mechanical,

and chemical energy.Ex: Thermal energy heats our atmosphere, water bodies, and land

surfaces, which can transfer that heat to other things! This influences wind

patterns. When air is heated, its molecules move apart and the air

becomes less dense, causing it to rise. ( “convection”)

Sunlight also is the energy source that provides us with food via

photosynthesis!

Stormy Weather• What causes warm, tropical air to rise?

• What happens to air pressure as a storm approaches?

• What region of Connecticut gets colder temperatures and more snow? Why???

• What is the relationship between “convection” and “sea breezes”?

See Previous Slide

Decreases (goes down)

Northwest…higher elevation & cannot benefit from ocean’s moderating effect

See NEXT Slide

Content Standard 6.5

• Work is the process of making objects move through the application of force.

• Energy can be stored in many forms and can be transformed into the energy of motion.

See how much you already know about simple machines with this

fun online interactive game!Name 3 household items &

tell what kind of machine they are!

Let’s visit the skate park to understand the relationship

between potential and kinetic energy!

On the right, click on “Bar Graph”

What happens to potential energy as kinetic energy goes up & vice versa?As K.E. goes up,

P.E. goes down (and vice versa!)

Content Standard 7.2 a

• All organisms are composed of one or more cells; each cell carries on life-sustaining functions

View this CELL ANIMATION

List two differences and two similarities of plant

& animal cells!BOTH: Nucleus, DNA,

Mitochondria, Cell membrane

PLANT ONLY: Chloroplasts & Cell walls

Content Standard 7.2 b

• Multicellular organisms need specialized structures & systems to perform basic life functions

Visit this RESPIRATORY SYSTEM

tutorial! * What muscle controls breathing?

Watch this DIGESTIVE SYSTEM animation!

* Where does “chemical digestion” occur?

Visit this tutorial about body joints!

*Give one example of 3 types of joints!

A student carries out an experiment to determine if music type has an effect on

heart rate.

Study the graph on the following slide and respond to the corresponding questions.

What is the independent variable in this investigation?

What is the dependent variable in this investigation? Write a conclusion for this investigation.

Hint: When you answer an open-ended question, try using the word “because” or “for example”

Content Standard 7.3

• Landforms are the result of the interaction of constructive and destructive forces over time.

The image above shows the Pacific’s

“Ring of Fire” Name three different geologic

features that are often associated with the boundaries of the Ring of

Fire Volcanoes, Mountains, Trenches, Ridges, etc.

What agents of erosion formed this butte? Wind & Water!!

Content Standard 8.1 b

• An unbalanced force acting on an object changes its speed and/or direction of motion.

A student carries out an experiment to determine ways to keep shipping

containers from sliding along the deck of a ship.

Study the data table on the following slide and respond to the corresponding questions.

Type of surfaceForce (N) to pull 1 Kg a distance

of 10 cm

Sandpaper 1.2

Cloth .2

Hard Plastic .3

What surface would you recommend for a boat deck to reduce the amount of sliding during transit? Support your

choice with data!

Content Standard 8.2

• Reproduction is a characteristic of living systems & is essential for the continuation of every species

Watch the MITOSIS Animation

Stop at each stage to review the steps!

Watch the MEIOSIS AnimationStop at each stage to

review the steps!

MITOSIS MEIOSIS

1.Number of cells produced

2. Where it occurs

3. Number of chromosomes in each resulting human cell

Copy this chart and use it to compare mitosis to meiosis.

2 4

All Somatic Cells Testes/Ovaries

46 23

Content Standard 8.4

• Bridges can be designed in different ways to withstand certain loads and potentially destructive forces.

Use the vocabulary words provided in the list above to write one concise & accurate sentence about each of the bridges shown

above.

beam, force, truss, suspension,

horizontal, vertical, cable, push, pull, bend, squeeze, load, joints, span,

compression, pillar, abutment

Test your skills with this interactive bridge challenge!

OOPS! Need some review?

Check out this fun, online interactive about forces, loads, materials, and shapes!

Scientific Numeracy

• Scientific numeracy includes the ability to use mathematical operations and procedures to calculate, analyze and present scientific data and ideas.

KILOKnights

HECTOHunt

DEKADragons

(base unit)

because

DECIDragons

CENTIChase

MILLIMaidens

.026 .26 2.6 26 260 2,600 26,000

.0046 .046 .46 4.6 46.0 460 4,700

Hint: Biggest to smallest, LEFT to Right!

Use the values given in the table below in order to complete the rest of the table.

Name one metric unit associated with each of these measuring tools.

mm, cm, etc.

Degrees Celsius

g, Kg, etc.

L, ml, etc.