Science grade 9 exams prep

At midnight, what process are the cells of a plant doing?

cellular respiration

What do decomposers do for the environment

they convert large molecules into simpler molecules that can then be recycled

is fog a form of precipitation

no

what are all living things made up of

carbon

Is carbon the most abundant element in the universe

no

what does burning fossil fuels do with carbon dioxide

resleases more of it into the atmosphere

what does denitrifying bacteria do

return nitrogen to the atmosphere

What is an organism that eats producers or other consumers called

heterotroph (consumer)

What is a population

All the members of the SAME SPECIES living in the same ecosystem

What is a community

The collection of ALL THE POPULATIONS of the DIFFERENT SPECIES in an ecosystem

what is an ecosystem

A defined area where certain populations interact

what is a niche

a specific role/place occupied by an organism in the environment

what is a habitat

the conditions required for an orgainism to live

what is a tropical rainforest an example of

ecosystem

what is the muddy bottom of a pond an example of

habitat

All the dandelions growing on a school field are a…

population

the open ground where dandelions grow is a…

habitat

what is the word equation for photosynthesis

carbon dioxide+water+sunlight—>oxygen+sugar

what is the word equation for cellular respiration

glucose+oxygen—>carbon dioxide+water+energy

What happens in the carbon cycle

carbon atoms travel between four reservoirs

atmosphere, land, oceans, living organisms

plants absorb it from the atmosphere

animals get it from eating plants

fossil fuels combust to get released into the atmosphere

what happens in the nitrogen cycle

moves through atmosphere, soil, water, living organisms

bacteria fixes the atoms into plant roots

Animals can get the nitrogen from eating the plants

when biotics die the nitrogen returns to the soil

denitrifying bacteria returns the nitrogen into the atmosphere as a gas

in a series circuit, current is different everywhere

false

it is the same everywhere

how is voltage split in a series circuit?

proportional to resistance for each load

(V1=IxrR)

does a load get more voltage with higher resistance?

Yes

In a parallel circuit, do electrons only go through one loop each time they run the circuit?

Yes. They only can go through one each time they go around.

What does it mean if an electron can only loop through one circuit at a time in a parallel circuit for voltage?

it means they share all of the total voltage with the load in the loop

what is the equation for the total current in a parallel circuit

iT=i1=i2+…

in a parallel circuit, which path is an electron more likely to travel through?

the one of least resistance (1 ohm opposed to five ohms)

What is it called when the charge builds up and doesn’t move

static

What happens when one previously charged object touches a neutral object

The neutral object gets a charge

results in both having the same charge

What happens when a charged object is brought close to a neutral object

The charges in the neutral object rearrange so that the opposite of the charged object is closer to it.

Makes one side of the neutral object positive and one side negative

How do you make charging by induction permanent

Grounding the object (touching it against something so that the electrons can escape, and then taking away that thing so that the protons stay in the first object but not the electrons)

def of static electricity

the buildup of an electrical charge on the surface of materials caused by an imbalance between positive and negative charges

What happens if a positive object touches a neutral object

the positive object pulles

What are the three main hazard groups?

1. Physical

2. Health

3. Environmental

What are some examples of physical properties?

colour, melting point, boiling point, density, flexibility, strength, conduction of heat or electricity

(determined by looking or handling)

What are some examples of chemical properties?

flammability, ph (acidity), toxicity, reactivity

(determined by testing or chemical reactions)

What group are alkali metals in?

group 1

What group are halogens in?

group 7

what group are noble gases in?

group 8

What do periods determine in bohr diagrams?

the number of energy shells in the diagram

What are some physical properties of metals

high melting points

all solid (except mercury)

good conductors

high density

malleable

ductile

sonorous

What are some physical properties of non-metals

low melting points

solids, liquids, and gases

poor conductors

low density

non malleable

non ductile

non sonorous

alkali chem properties

Very reactive with water

halogen chemical properties

very reactive

very toxic

noble gas chem properties

non-flammable

unreactive in most cases

What is particle theory?

A way to describe the structure of matter and its behaviour.

all matter is composed of particles.

All particles have space between them

particles present in matter are always in motion

the particles in a substance attract each other

what is mass?

mass is a measure of the quantity of matter in an object

what is an atom?

the smallest part of an element that has all the element’s properties

what is atomic theory?

the study of the nature of atoms and how they combine to form all types of matter.

What did dalton add to atomic theory

he said atoms are small spheres with unique properties and they can be combined (billiard ball model)

what did thomson add to atomic theory

found atoms are a combination of particles (electrons) which are negatively charged

(plum pudding model)

what did rutherford add to atomic theory?

conducted gold foil experiments and proved atoms are not spheres

they have a nucleus (positive) surrounded by electrons (negative)

what did chadwick add to atomic theory

discovered that the nucleus has neutrons and protons

what did bohr add to atomic theory

found that electrons are on specific energy levels

they cannot be in the space between

they move by gaining or losing energy

symbol

mass

charge

location (proton)

p+

1

+1

nucleus

symbol

mass

charge

location (neutron)

n0

1

0

nucleus

symbol

mass

charge

location (electron)

e-

~0

-1

energy levels around the nucleus

how many shells do elements in the first period have

1

how many shells do elements in the 2nd period have

2

what would [2,8,1] look like in a bohr diagram

2 electrons 1st shell

8 electrons 2nd shell

1 electron valence shell

what does the group number determine for bohr models

the number of valence electrons

identify the number of atoms

Cr²(CO^4)³

Chromium 2

carbon 3

oxygen 12

What is it called if an element loses an electron?

It is an ion of the element

Can an element lose a proton and still be the same element?

no, it will change.

Can an element lose an electron and still be the same element?f

yes, it will become an ion.

What is the chronological order of the researchers that studied atomic theory

1. Democritus

2. Dalton (thought of atoms as tiny solid balls)

3. Thomson (discovered electrons)

4. Rutherford (discovered protons)

5. Bohr (discovered energy shells)

6. Chadwick (discovered neutrons)

whose model

Dalton

whose model

Thomson

whose model

Rutherford

whose model

Bohr

whose model

Chadwick

what are atoms with the same number of protons but a different number of neutrons?

isotope

does an elements atom change when an electron leaves?

No, it turns into an ion because the number of protons defines the element

What happens if a proton is taken from an element?

The element will change because the number of protons defines the element

True or false: the number of electrons defines the element

false: the number of protons defines the element

True or false: Rutherford discovered energy shells

false: he discovered protons (gold foil exp)

True or false: Dalton’s model is called the plum pudding model

Dalton’s model is called the billiard ball model

plum pudding = thomson

True or false: the period defines the number of energy shells

True

What does WHMIS stand for?

Workplace Hazardous Materials Information System

explosive

flammable

oxidizing-they give off oxygen that could fuel fire

gas cylinder-gases under pressure

corrosive-burn through metals, skin, etc

toxic/poison

health hazard-may cause serious health effects

exclamation mark-may cause less serious health effects or damage the ozone layer

Environment-may cause damage to the aquatic environment

biohazardous infectious materials-organisms or toxins that can cause diseases

Hazard groups

physical, health, environmental

this CONTAINER can EXPLODE

This PRODUCT can BURN (CORROSIVE) on contact

This PRODUCT can CATCH FIRE

this PRODUCT can CAUSE ILLNESS OR DEATH (POISON) IF INGESTED

a TRIANGLE for hhps stands for

the container is hazardous

an OCTAGON for hpps stands for

the product is hazardous

hhps stands for

Hazardous Household Product Symbols

whmis stands for

Workplace Hazardous Materials Information System