Science spiral 2 Flashcards
who is Democritus
he came up with the indivisible particle.
It’s made up of tiny pieces that cannot be broken down.
who is dalton
he came up with the billiard ball model,
atoms are small indivisible particles.
who is thomson
came up with the chocolate chip model.
Theory: negatively charged electrons are found inside a positive charge sphere
who is rutherford
the nuclear model
Theory: atoms are mostly empty space with a positively charged centre
what do elements of the same group have
same number of valance electrons
Which group is each chemical family in and how many valence electrons does each have
alkali- group 1- 1 valance electron
alkaline earth metals group 2- 2 valance electrons
Halogen- group 7/17 - 7 valence electrons
Noble gases- group 8/18- 2/8valence electrons
who is chadwick
model: The planetary model
Theory: nucleus contains neutral particles along with the positively charged particles
who is Bohr
model: Rutherford- bohr model
Theory: electrons surround the nucleus in specific energy levels
5 metal properties
-solid (except mercury)
-shiny
-good conductors
-malleable
-ductile
5 non- metal properties
-solid, liquid, gas,
-dull (not shiny)
-poor conductors
-brittle
-not ductile
whats a period
horizontal rows
groups
vertical columns
4 chemical family
alkali
alkaline earth metals
halogens
nobel gases
standard atomic notation
-Write the element short form
-mass number on top
-protons on bottum
where are subatomic particles located
protons- nucleus
neutrons- nucleus
-electrons - orbitals around the nucleus
charge of subatomic particles
protons - positive
-neutrons- neutral
-electrons- negative
whats an isotope
atoms of the same element that have different numbers of neutrons
orbital trends
the period it is, determines how many orbitals the elemten has
atomic radius
the size of the atom
How many electrons fit in the first second and third orbital
1-2
2-8
3-8
Elements vs. Compounds:
Elements: A pure substance that cannot be broken down into simpler substances. ( hydrogen, sodium, oxygen, chlorine etc.)
Compounds: A pure substance that contains 2 or more different elements in a fixed ratio. ( salt, sugar, water, carbon dioxide etc.)
Atom vs. Element:
Elements are a pure substance and Atoms are the smallest units of elements
Why are atoms neutral?
Atoms contain the same number of protons and electrons making their overall charge always neutral.
what is Static Electricity
The buildup of an electric charge on the surface of an object.
Charging by conduction (contact):
when Two objects have a DIFFERENT charge
Charging by friction:
Two objects are NEUTRAL
Charging by Induction (temporary)
Temporary: Holding a charged object close to a neutral object creates an induced charge on the neutral object.
charging by induction permanently
Permanent: An induced charge in neutral objects can be made permanent by grounding the object on the side furthest from the charged object.
What is the difference between a temporary and permanent charge?
A temporary induced charge is where a charged object is brought close to (but not touching) a neutral object but a permanent induced charge needs the neutral object to be grounded as well.
What are the 3 laws of electric charges?
Objects with the same charge repel each other
Object with opposite charges will attract each other
Charged objects attract neutral objects
How to charge an object using friction
Rubbing one object together with another object will cause the electrons to transfer to another material.
Net charge
Overall charge of the atom
Grounding
Connecting an object to the earth’s surface using a conductor
Discharging (water vapor):
Moisture in the air can act as a pathway for electrons, humid air draws more electrons than dry air
Big bang theory:
All of the matter and energy in the universe expanded from a single point
What was the first atom to be created in the universe?
Hydrogen
Nebula
cloud of gas and dust
Nuclear fusion:
The process that takes place in the core of the sun (merges atoms together)
3 possible life paths for stars
Low Mass Nebela, Medium Mass Nebela, and High Mass Nebela.
Low Mass Nebela
Nebula– Protostar–Red Dwarf–White Dwarf
Medium Mass Nebela
Nebula–Protostar–Red Giant–Planetary Nebula–White Dwarf–Black Dwarf
High Mass Nebela
Nebula–Protostar–Red supergiant–Supernova–Neutron star and Black hole
Supernova:
Stars that eventually died creating a massive explosion called supernova.
Reservoirs:
an area where carbon is stored for long period of time
Biotic Reservoirs:
Carbon trapped in the cells of living organisms. (forests, fossil fuels, shells, bones)
Abiotic Reservoirs
Carbon stored in the environment. (Lakes, Rivers, the ocean)
Carbon Deposits:
ways which carbon can get trapped underground. ( fossil fuels (coal, oil, natural gas) that form when decomposed organisms are compressed over long periods)
3 ways humans add carbon to the environment:
Burn fossil fuels
Cut down trees (Deforestation)
Pollute the air with car emissions
Burning fossil fuels
releases carbon in that reservoir adding more carbon into the atmosphere.
Cutting down trees (Deforestation)
means less CO2 removed from the atmosphere for Photosynthesis. Any carbon trapped in these trees is then released into the atmosphere.
Polluting the air with car emissions
air pollution from cars adds more carbon into the atmosphere and this can actually result in acid rain forming.
Decomposers
return carbon trapped in the bodies of organisms back to the atmosphere in the form of CO2.
2 complementary processes’ balancing the carbon cycle:
Carbon is recycled in the carbon cycle through several processes but mostly through photosynthesis and cellular respiration.
Why is algal bloom bad for plants
Blocks the sun, preventing them from undergoing photosynthesis.
Eutrophication:
excess nitrogen entering run-off in nearby lakes and ponds.
Algal Bloom
Layer of algae that grows on the surface of water.
Human activities disrupting the nitrogen cycle:
Fertilizers–Excess Nitrogen in Run-Off–Eutrophication–Algal Bloom
What do humans add to fertilizers to help plants grow and why is too much of this thing bad?
They add nitrogen and excess fertilizers can damage aquatic ecosystems.
Which bean boosts nitrogen content in soil?
Legumes
Crop Rotation–
Some farmers rotate between their regular crops and legume plants
Three sisters–
Corn (provide a lattice for beans to grow on), Beans (provide nitrogen to the soil for corn and squash), and Squash (provides moisture to the soil for beans and corn)
Why is bacteria the most important part of the nitrogen cycle?
Bacterias are necessary for “fixing” the nitrogen so it can be used by plants.
Human influence impact the nitrogen cycle:
Humans use too much nitrogen in fertilizers– excess nitrogen goes into a lake/pond (eutrophication)– Algae increase in number (algal bloom)– block sunlight from reaching plants in water– No photosynthesis– Plants dead
