CHAPTERS: 1-3 Flashcards
what is photosynthesis?
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
word equation for photosynthesis?
carbon dioxide + water -> glucose + water
what is chlorophyll?
a green pigment that is found in chloroplasts within plant cells and transfers energy from light into energy in chemicals
what’s glucose for?
- used in respiration to release energy for cell
- converted to starch for storage
- converted to fat + oils in seed
- converted to sucres then transported to all parts of plants
- combined with nitrates from soil -> amino seeds -> proteins
what is a stoma(ta)?
it is a tiny hole in the lower epidermis, the holes let carbon dioxide from the air get into the leaf
explain the process of climate change:
- energy from the sun passes through the atmosphere and warms the surface of the ground
- some of the energy that reaches the ground is reflected
- some of the reflected energy passes back out through the atmosphere and is lost to space
- some of the reflected energy is blocked by the carbon dioxide in the atmosphere, so it stays close to the earth
what is slush?
slush is melting ice
what is mass extinction?
this is when species vanish much faster than they are replaced
what is meteorites?
the parts of meteoroids that do collide with earth
what is meteoroids?
objects in space that are smaller than an asteroid
what is meteors?
when meteoroids enter earth’s atmosphere
what is an atom?
an atom is the smallest particle of an element that can take part in a chemical reaction
protons…
- positively charged
- located in nucleus of atom
electrons…
- negatively charged
- located in the energy levels surrounding an atom
- they are held in place by electrostatic forces
neutrons…
- these are neutral, they have no charge
- they are located in the nucleus of an atom
the atomic number is located on…
the top
the mass number is located on…
the bottom
when do molecules occur?
when you share electrons
when do ions occur?
they form when they loose or gain an electron
how do we know how many protons there are?
the atomic number tells you that/top number
how do we know how many electrons there are?
the atomic number tells you that/top number
how do we know how many neutrons there are?
atomic number subtracted by the mass number/atomic number-mass number
what is an ionic bond?
when there is an attraction between the positively charged ion and the negatively charged ion
what are ionic compounds?
those that are made from ions, when a metal reacts with a non-metal
what is a covalent bond?
a type of chemical bond where electrons are shared
when are covalent molecules formed?
when atoms of different non-metals join together to form compounds and when atoms of the same non-metal join together
what are macromolecules?
they are joined structures
ionic substances…
- 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
covalent substances…
- 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
ionic + ionic =
element
covalent + covalent =
compound
what is density?
property (space & volume) of an object
what is mass?
measurement of an object (g/kg)
what is volume?
measurement of an object in 3D
how do we calculate density?
mass / volume
how do we calculate volume?
mass / density
how do we calculate mass?
volume x density
what is heat?
measures the total thermic kinetic energy of vibrating particles
what is temperature?
measures the average thermal kinetic energy of the particles
what is a regular shape?
shape having a volume that can e calculated using an equation
what is an irregular shape?
shape having a volume that cannot be calculated using an equation
energy…
- is measured in joules (J)
- is stored/conserved
- can be transferred
- cannot be created or destroyed
what is dissipation?
it describes the movement of energy from a hot to cold place
heat can be transferred by three main processes…
- conduction
- convection
- radiation
what is conduction?
- when particles are very close together can transfer heat energy as they vibrate
- only occurs in solids
which solids do not conduct heat?
paper, glass, rubber, porcelain, ceramic, plastic
what is convection?
this upward movement of warmer liquid/gas
what is a convection current?
the movement around the heated liquid/gas
how does heat travel?
infrared waves
infrared waves…
- can travel through a vacuum
- travel at the same speed of light
- can be reflected/absorbed
what is thermal radiation?
when infrared heat objects that absorbs
absorber
a material that takes in thermal radiation
conduction
the method of heat transfer in solids
conductor
a material that lets heat flow through
convection
the method of heat transfer in fluids, which occurs because hot fluids are less dense than cold fluids
emitter
a material that gives out thermal radiation
free electrons
electrons in a metal that are free to move through the metal
heat transfer
the flow of heat energy from a hotter area to a colder area
radiation
heat energy transferred by infrared waves, this method of heat transfer does not need particles
