🧪 SCIENCE STUDY NOTES – Skills, Chemistry, and Ecosystems

Question 1

What is an independent variable in an experiment?

Answer 1

What you change.

Question 2

What is a dependent variable in an experiment?

Answer 2

What you measure.

Question 3

What is a controlled variable in an experiment?

Answer 3

What stays the same.

Question 4

What does it mean for an experiment to be reliable?

Answer 4

Same results every time.

Question 5

What does it mean for an experiment to be accurate?

Answer 5

Results are close to the real answer.

Question 6

What does it mean for an experiment to be valid?

Answer 6

The experiment is fair and tests the right thing.

Question 7

Define an element.

Answer 7

A pure substance (e.g. Oxygen).

Question 8

Define a compound.

Answer 8

Two or more elements joined (e.g. Water = H₂O).

Question 9

Define a mixture.

Answer 9

Substances mixed but not joined (e.g. Saltwater).

Question 10

What is the symbol for Hydrogen?

Answer 10

H

Question 11

What is the symbol for Helium?

Answer 11

He

Question 12

What is the symbol for Lithium?

Answer 12

Li

Question 13

What is the symbol for Beryllium?

Answer 13

Be

Question 14

What is the symbol for Boron?

Answer 14

B

Question 15

What is the symbol for Carbon?

Answer 15

C

Question 16

What is the symbol for Nitrogen?

Answer 16

N

Question 17

What is the symbol for Oxygen?

Answer 17

O

Question 18

What is the symbol for Fluorine?

Answer 18

F

Question 19

What is the symbol for Neon?

Answer 19

Ne

Question 20

What is the symbol for Sodium?

Answer 20

Na

Question 21

What is the symbol for Magnesium?

Answer 21

Mg

Question 22

What is the symbol for Aluminum?

Answer 22

Al

Question 23

What is the symbol for Silicon?

Answer 23

Si

Question 24

What is the symbol for Phosphorus?

Answer 24

P

Question 25

What is the symbol for Sulfur?

Answer 25

S

Question 26

What is the symbol for Chlorine?

Answer 26

Cl

Question 27

What is the symbol for Argon?

Answer 27

Ar

Question 28

What is the symbol for Potassium?

Answer 28

K

Question 29

What is the symbol for Calcium?

Answer 29

Ca

Question 30

What are groups in the periodic table?

Answer 30

Columns (same properties).

Question 31

What are periods in the periodic table?

Answer 31

Rows (atomic number increases).

Question 32

List three properties of metals.

Answer 32

* Shiny * Bendy * Good conductors

Question 33

List three properties of non-metals.

Answer 33

* Dull * Brittle * Poor conductors

Question 34

What is a physical change?

Answer 34

Looks different, but still the same substance (e.g. ice melting).

Question 35

What is a chemical change?

Answer 35

Makes new substances (e.g. burning).

Question 36

What is evaporation in the water cycle?

Answer 36

Water turns to gas.

Question 37

What is transpiration in the water cycle?

Answer 37

Plants release water.

Question 38

What is condensation in the water cycle?

Answer 38

Gas turns to water (clouds).

Question 39

What is precipitation in the water cycle?

Answer 39

Rain, snow, etc. water released from clouds.

Question 40

Define ecology.

Answer 40

Study of living things and where they live.

Question 41

Define an ecosystem.

Answer 41

Living things + their environment.

Question 42

What does biodegradable mean?

Answer 42

Breaks down naturally (e.g. food scraps).

Question 43

Define biodiversity.

Answer 43

Lots of different living things.

Question 44

What are abiotic factors?

Answer 44

Non-living parts (e.g. sunlight, soil).

Question 45

What are biotic factors?

Answer 45

Living parts (e.g. animals, plants).

Question 46

What is a habitat?

Answer 46

Place where something lives.

Question 47

What is a niche?

Answer 47

What a living thing does in its habitat.

Question 48

What is photosynthesis?

Answer 48

Plants make food using sunlight.

Question 49

What is respiration?

Answer 49

Living things use oxygen to get energy from food.

Question 50

Define autotrophs.

Answer 50

Producers: Make their own food (plants).

Question 51

Define heterotrophs.

Answer 51

Consumers: Eat other living things.

Question 52

What do herbivores eat?

Answer 52

Plants (e.g. deer).

Question 53

What do carnivores eat?

Answer 53

Animals (e.g. lion).

Question 54

What do omnivores eat?

Answer 54

Both (e.g. humans).

Question 55

What do decomposers do?

Answer 55

Break down dead stuff (e.g. fungi, bacteria).

Question 56

What is a food chain?

Answer 56

Shows who eats who.

Question 57

What is a food web?

Answer 57

Many food chains connected.

Question 58

What is a primary consumer?

Answer 58

Eats plants.

Question 59

What is a secondary consumer?

Answer 59

Eats herbivores.

Question 60

What is a tertiary consumer?

Answer 60

Eats secondary consumers.

Question 61

What is a trophic level?

Answer 61

A level in a food chain.

Question 62

What does a food pyramid show?

Answer 62

How energy moves up each level.

Question 63

Define predator.

Answer 63

Hunts (e.g. eagle).

Question 64

Define prey.

Answer 64

Gets hunted (e.g. rabbit).

Question 65

What is the carbon cycle?

Answer 65

Carbon moves around in the air, plants, animals, and the Earth through breathing, burning, and decay.

Question 66

What is the energy source for most ecosystems?

Answer 66

The sun.

Question 67

What do producers do with sunlight?

Answer 67

Use sunlight to make food via photosynthesis.

Question 68

What percentage of energy is transferred from one trophic level to the next?

Answer 68

~10%.

Question 69

What percentage of energy is lost to the environment at each level?

Answer 69

~90%.

Question 70

What are three ways energy is lost to the environment?

Answer 70

* Heat * Movement * Waste * Metabolism

Question 71

If the producer level has 1000 MJ of energy, how much energy does the tertiary consumer get?

Answer 71

1 MJ.