GRADE 9 Science exam

What’s a compound

When a substances particles are composed of diffrent atoms

What percent of energy gets passed down to trophic levels

10%

What’s an Element

When a substance particles are composed of one type of element

What’s a pure substance?

When all particles of a substance have the same chemical properties. One type of particle

What is mixture?

Contains diffrent types of particles

What is particle theory of matter (5)

1. All matter is made of tiny particles

2. All particles of the same substance are made of the same particle

3. All particles have spaces in between them

4. Particles are always in motion

5. Particles attract each other

Define homogenous

Components of the mixture are fully combined. Uniformly distributed.

Define heterogenous

Components are not uniformly distributed in the mix

Solid to Liquid

Melting

Solid to gas

Sublimation

Liquid to gas

Vaporization

Liquid to solid

Freezing

Gas to liquid

Condensation

Gas to solid

Deposition

Define physical property

Description of an object using five senses

Name 3 qualitative properties

Lustre

Clarity

Viscosity

Malleability

Ductility

Brittleness

Name 3 quantitative properties

Freezing or boiling point

Melting point

Density

Define chemical property

Ability to react with another substance, creates a new substance.

Physical change?

The substance is the same

Chemical change?

A new substance forms

Name 5 chemical change signs

1. New colour

2. New smell

3. Energy/temperature change

4. Precipitate

5. Bubbling

Number of protons in an atom?

Atomic number

Number of electrons in an atom?

Number of protons

Number of neutrons in an atom!

Atomic mass - number of protons

Atomic mass?

Number of protons - number of electrons

Where are groups in periodic table and what do they tell?

Groups are vertical and they tell number of valence electrons

Where are periods in the periodic table and what do they tell?

Periods are horizontal and they tell number of shells in an element

Name 4 chemical families and their corresponding group number

Alkali metals - 1

Alkali earth metals - 2

Halogens - 17

Noble gases - 18

What’s static electricity?

Buildup of electric charge on the surface of objects

Friction process and key points

• rubbing together

• Both objects start neutral

• After, one is negative and the other is positive charged

Process of induction and key points

• bringing it close

• Temporary charge separation

• One object is neutral and the other is charged

Process of conduction and its key points?

• they touch

• Two objects with different charges come in contact

• Electrons move from more negative to less negative object

• Results in same net charge

Ways to lower resistance

• lower temperature

• Thicker wire

• Shorter wire

Resistors in circuits?

• higher resistance in series

• Lower resistance in parallel

What is the current, voltage and resistance formula in series?

Current is same

Voltage is added up all

Resistance is added up all

What is current voltage and resistance in parallel

Current is added up all

Voltage is same everywhere

Resistance is (1/Rtotal = 1/r1 + 2/r2 and so on)

What is current?

The rate of the flow of electrons through an circuit

What is voltage

Energy keeping electrons moving through the circuit

What is resistance

Amount of pushback the electrons receive during their route

Define ecology

Study of interactions between organisms and their environment

Define ecosystems

Set of living organisms and their physical and chemical environment

What are the four spheres

Hydrosphere

Atmosphere

Biosphere

Lithosphere

Organization of life in order

Individual

Population

Community

Ecosystem

Biome

Biosphere

What is the energy source?

The sun. All energy comes from the sun

What are producers

Organisms that make their own food using sunlight or chemical energy

What are consumers

Organisms that eat other organisms to gain energy

What are decomposes

Organisms that break down dead meat and recycle nutrients

A stable ecosystem consists of…

Large amount of producers, a lot of herbivores, and few carnivores

What’s a food chain

Linear sequence showing who eats who in an ecosystem

What’s a food web

A network of food chains in an ecosystem

Tropic levels and their description

Producers - plants

Primary consumers - herbivores, eats producers

Secondary consumers - Xarnivores or omnivores. Eats primary

Tertiary consumers - carnivores. East secondary

Quaternary consumers - Apex predators

Decomposes - breaks down dead organisms but not part of pyramid

Mutualism?

Both species benefit

Commensalism?

One species benefits while other is unaffected

Parasitism

One species benefits and the other is disadvantage

Predation

One species hunts and eats other species

Competition

Both species fight over same food source. Both disadvantaged

Define carrying capacity

The maximum population size of a species that an ecosystem can sustain

Define limiting factor

A factor in the environment that controls growth of a population of organisms in an ecosystem

What are some biotic factors

Food

Mates

Competition

Predation

Diseases

Invasive species

Some abiotic factors?

Sunlight

Rain

Water

Wind

Soil type

Space

Shelter

Temperature and climate

Carbon is recycled through…

Photosynthesis and cellular respiration

Name all steps of carbon cycle

1. Carbon moves from atmosphere to found

2. Carbon moves from plants to animals

3. Carbon moves from animals or plants to ground

4. Carbon returns to atmosphere

what’s carbon sinks and examples

Anything that absorbs more carbon than it intakes. Forests, oceans, soil, etc.

Define photosynthesis

Process of plants making own food

Formula for photosynthesis

Carbon dioxide + water + sunlight — sugar + oxygen

Define cellular respiration

Process by which animals get energy

Formula for cellular respiration

Sugar + oxygen —> co2 + water + energy

Photosynthesis and cellular respiration are…

Commentary processes

Name all steps of nitrogen cycle

1. Nitrogen enters soil from atmosphere

2. Nitrogen moves up food chain

3. Nitrogen moves back to ground through waste and death

4. Nitrogen enters atmosphere

What’s nitrogen fixation?

Bacteria turning nitrogen gas to ammonia for soil and plants to use. First step in nitrogen cycle

What’s nitrification

Ammonia is converted into nitrites and nitrates so plants can absorb them easily

What’s denitrification

Nitrites and nitrates are converted back into nitrogen gas and returned to the atmosphere

Define tolerance range

Range in which species will survive

Define optimal range

Best range of abiotic factors that allow population to thrive

Causes of biodiversity loss?

HIPPOC

Habitat loss

Invasive species

Pollution

Population

Over harvesting

Climate change

What’s the greenhouse effect process

1. GHG traps sun energy to keep planet warm

2. Any energy not absorbed is bounced or reflected off

3. That same energy is released back over time

What are greenhouse gases and name 3

Any gas that absorbs infrared radiation in the atmosphere

Carbon dioxide, methane, nitrogen oxide

Define the universe

Region that contains all of space and all forms of matter and energy

Define galaxy and its three types

System of stars held together by gravity

Barred spiral, Elliptical, irregular

What is the big bang theory

1. 13.8 billion years ago or 13 billion years ago

2. Space was infinitely small, very hot and dense

3. Then it started expanding rapidly which cooled it down

4. Spade between matter increases.

Evidence for big bang

Red shifts, the further the object the more light stretches by the time it reaches us

Cosmic microwave radiation, created after big bang and spread in all directions

Abundance of light elements, a lot of hydrogen and helium

Define solar system

A group of planets, moons, asteroid that orbit a star

Planet requirements

Must orbit a star

Mostly round

Big enough that gravity cleared other objects in its orbit

Inner planet characteristics?

Mercury Venus earth mars

• rocky and terrestrial

• Solid surfaces

• HOT

Outer planet characteristics

Jupiter Saturn Uranus Neptune

• gas giants or water giants

• Bigger and less dense

• COLD

Where is asteroid belt

Between mars and Jupiter

What are stars

Giant spheres of hot glowing gas

Process of nuclear fusion?

• happens in core of a star

• hydrogen atoms fuses with each other

• Turns into helium

• Releases energy in starlight

Name two ways a stars life can proceed

Stellar nebula - average star - red giant - planetary nebula - white dwarf

Stellar nebula - massive star - red supergiant - supernova - black hole OR Neutron star

Stellar nebula?

Big cloud of hydrogen gas

Forms new stars

Average and massive star?

When core gets hot enough, nuclear fusion.

Adult stars that are big or small

Red giant

Star runs out of hydrogen in its core

Swells and expands

Core heats up

Fuses helium into carbon

Planetary nebula

Helium is red giant used up

Star ejects materials outwards

White dwarf?

Center of planetary nebula

Small and dense and dosnt fuse

Stays cooling forever

Red supergiant

Bigger red giant

Supernova

When core of red super giant collapses

Massive explosion

Spreads heavy elements into space

Later forms stars and planets

Neutron star

DENSE

Black hole

Alternative end for high mass stats

Gravity strong nothing escape

Which planets don’t have moons

Mercury and Venus