CHAPTERS: 1-3

Question 1

what is photosynthesis?

Answer 1

a process by which green plants manufactures sugars (food) using carbon dioxide and water in the presence of sunlight and chlorophyll to produce glucose and oxygen gas

Question 2

word equation for photosynthesis?

Answer 2

carbon dioxide + water -> glucose + water

Question 3

what is chlorophyll?

Answer 3

a green pigment that is found in chloroplasts within plant cells and transfers energy from light into energy in chemicals

Question 4

what’s glucose for?

Answer 4

1. used in respiration to release energy for cell
2. converted to starch for storage
3. converted to fat + oils in seed
4. converted to sucres then transported to all parts of plants
5. combined with nitrates from soil -> amino seeds -> proteins

Question 5

what is a stoma(ta)?

Answer 5

it is a tiny hole in the lower epidermis, the holes let carbon dioxide from the air get into the leaf

Question 6

explain the process of climate change:

Answer 6

1. energy from the sun passes through the atmosphere and warms the surface of the ground
2. some of the energy that reaches the ground is reflected
3. some of the reflected energy passes back out through the atmosphere and is lost to space
4. some of the reflected energy is blocked by the carbon dioxide in the atmosphere, so it stays close to the earth

Question 7

what is slush?

Answer 7

slush is melting ice

Question 8

what is mass extinction?

Answer 8

this is when species vanish much faster than they are replaced

Question 9

what is meteorites?

Answer 9

the parts of meteoroids that do collide with earth

Question 10

what is meteoroids?

Answer 10

objects in space that are smaller than an asteroid

Question 11

what is meteors?

Answer 11

when meteoroids enter earth’s atmosphere

Question 12

what is an atom?

Answer 12

an atom is the smallest particle of an element that can take part in a chemical reaction

Question 13

protons…

Answer 13

• positively charged
• located in nucleus of atom

Question 14

electrons…

Answer 14

• negatively charged
• located in the energy levels surrounding an atom
• they are held in place by electrostatic forces

Question 15

neutrons…

Answer 15

• these are neutral, they have no charge
• they are located in the nucleus of an atom

Question 16

the atomic number is located on…

Answer 16

the top

Question 17

the mass number is located on…

Answer 17

the bottom

Question 18

when do molecules occur?

Answer 18

when you share electrons

Question 19

when do ions occur?

Answer 19

they form when they loose or gain an electron

Question 20

how do we know how many protons there are?

Answer 20

the atomic number tells you that/top number

Question 21

how do we know how many electrons there are?

Answer 21

the atomic number tells you that/top number

Question 22

how do we know how many neutrons there are?

Answer 22

atomic number subtracted by the mass number/atomic number-mass number

Question 23

what is an ionic bond?

Answer 23

when there is an attraction between the positively charged ion and the negatively charged ion

Question 24

what are ionic compounds?

Answer 24

those that are made from ions, when a metal reacts with a non-metal

Question 25

what is a covalent bond?

Answer 25

a type of chemical bond where electrons are shared

Question 26

when are covalent molecules formed?

Answer 26

when atoms of different non-metals join together to form compounds and when atoms of the same non-metal join together

Question 27

what are macromolecules?

Answer 27

they are joined structures

Question 28

ionic substances...

Answer 28

- made from ions form giant lattices - they have very high melting points due to the strong ionic bond - when dissolved/melted, they can conduct electricity

Question 29

covalent substances...

Answer 29

- made from simple molecules - they have low melting points/boiling points due to the weak forces between molecules - when sharing electrons, they can form large structures like macromolecules - macromolecules have high melting points because they're joined by strong covalent bonds - simple covalent molecules do not conduct electricity

Question 30

ionic + ionic =

Answer 30

element

Question 31

covalent + covalent =

Answer 31

compound

Question 32

what is density?

Answer 32

property (space & volume) of an object

Question 33

what is mass?

Answer 33

measurement of an object (g/kg)

Question 34

what is volume?

Answer 34

measurement of an object in 3D

Question 35

how do we calculate density?

Answer 35

mass / volume

Question 36

how do we calculate volume?

Answer 36

mass / density

Question 37

how do we calculate mass?

Answer 37

volume x density

Question 38

what is heat?

Answer 38

measures the total thermic kinetic energy of vibrating particles

Question 39

what is temperature?

Answer 39

measures the average thermal kinetic energy of the particles

Question 40

what is a regular shape?

Answer 40

shape having a volume that can e calculated using an equation

Question 41

what is an irregular shape?

Answer 41

shape having a volume that cannot be calculated using an equation

Question 42

energy...

Answer 42

- is measured in joules (J) - is stored/conserved - can be transferred - cannot be created or destroyed

Question 43

what is dissipation?

Answer 43

it describes the movement of energy from a hot to cold place

Question 44

heat can be transferred by three main processes...

Answer 44

1. conduction 2. convection 3. radiation

Question 45

what is conduction?

Answer 45

- when particles are very close together can transfer heat energy as they vibrate - only occurs in solids

Question 46

which solids do not conduct heat?

Answer 46

paper, glass, rubber, porcelain, ceramic, plastic

Question 47

what is convection?

Answer 47

this upward movement of warmer liquid/gas

Question 48

what is a convection current?

Answer 48

the movement around the heated liquid/gas

Question 49

how does heat travel?

Answer 49

infrared waves

Question 50

infrared waves...

Answer 50

- can travel through a vacuum - travel at the same speed of light - can be reflected/absorbed

Question 51

what is thermal radiation?

Answer 51

when infrared heat objects that absorbs

Question 52

absorber

Answer 52

a material that takes in thermal radiation

Question 53

conduction

Answer 53

the method of heat transfer in solids

Question 54

conductor

Answer 54

a material that lets heat flow through

Question 55

convection

Answer 55

the method of heat transfer in fluids, which occurs because hot fluids are less dense than cold fluids

Question 56

emitter

Answer 56

a material that gives out thermal radiation

Question 57

free electrons

Answer 57

electrons in a metal that are free to move through the metal

Question 58

heat transfer

Answer 58

the flow of heat energy from a hotter area to a colder area

Question 59

radiation

Answer 59

heat energy transferred by infrared waves, this method of heat transfer does not need particles