finals study cards

periodic tabel

table of elements which are pure substance that cannot be broken into simpler substance by any means. Aprox. 90 of them occur naturally and chemist have created 25 extra. sbstance is element if on tabel. when joined they are compounds.

element symbol

abbreviation for a chemical elemant.

alkaline earth metals g2

denser and higher melting that g1, good conductor, quite reactive but less then g1, recrivity increases as you go down the family.

transution metals g 3-12

all metals: shiny, hard, and lustrous, most fround combined with other elements in ores, contains murcury the only metal liquid at room temp.

Pnictogens g15

metals, nonmetals nd metaloids, reactive: bonds with other elements by valence electrons, useful in small amounts dangerous in large, 5 valence elecrrons (needs three electrons to me stable), reactivity decreases as you go down family.

chalcogens g16

non metals and metaloids, oxygen ansn quite reactive, have 6 valence. Reactivity decreases as you go down group

stability of atom

when each of its orbitals have mamimum amount of electrons(eg. noble gas)

halogens g17

non metal (except astamine), means salt former, has 7 valnce electrons (can easily gain one to me stable), reactivity decreases as you go down family, most reactive non metal

element clesses

based on physical properties, all the elements can be divided into three classes: Metals, Non-metals, Metalloids

Metals

contains Most of the elements: They are solid and silver or grey in colour (except gold and mercury). They are good conductors of electricity and heat. They melt at high temperature.They are lustrous and malleable.They react with acids.

Non-Metals

Only 12 elements are non-metals. They are grouped together mainly because: They are found in all three states.11 are gases, 8 are solids and 1 is a liquid (bromine).Most common non-metals are carbon, oxygen, nitrogen and sulfur.The solid non-metals are poor conductors of electricity and heat. They are usually brittle.

Metaloids

remaining elements. have properties between metals and non-metals. solid at room temperature. conduct electricity but not well. used to make semiconductors. Most shiny and grey, but unlike a metal, are brittle

Noble Gases (Group 18)

Non-metals. All noble gases, they do not react with other elements. Used in various types of lighting. 8 valence electrons (except for He) which means it is stable

democritus 400bc

discouvered the atom or atamos meaning not to be cut

aristotle 450 bc

proposed four basic elements. earth, water, air, fire

john dalton 1807

porposed tiny invisible particles with different types for different elements. he said they could be rearanged but never created or distroyed

jj thompson 1897

hinted atoms were of even smaller particles, proposed the plum pudding` model, thought atoms weremase of a positive substance(protons) with nagative corpuscles scattered like rasins in pudding.

ernest rutherford

through expiraments, proposed a theory contrary to yhe plum pudding. theorised a neucleus of positive protons, surronded by cloud of electrons. but atom was mostly empty

neils bohr 1913

after studying hydrogen, hevised atomic theory to add electon orbits around neuclus(each with certian amout permissible) with each electron having energy,and ability to jump atom to atom.

james chadwick 1932

proposed that there element also contains a neutral particle called the neutron that is in the neucleus

subatomic particles

protons: positive, in neucleus, one amu, determine identity. neutrons: no charge, in neucleus, 1 amu, gives mass and holds atom together. electron: negative aprox. 2000x les that a amu, determine bonding and how it reacts.

atomic mas unit (amu)

metric unit used to measure mass of verry small objects (particles), such as atoms

atomic mass

decimal number on periodic table, number of protons plus average number of neutrons for all isotopes.

atomic number

number of protons in an atom for an element, same in all atoms of element, protons never leace neucleus, pariodic table is aranged in increasing atomic number

isotopes

atoms of same element with different numbers of neutrons

mass number

the amount of protons and neutrons an element has, determined by rounding atomic mass, always whole, not on periodic table

Bohr rutherford diagrams

determine number of protons, neutrons, and electrons. drae a small circle for neucleus. with protons snd neutrons inside. draw electron with orbitals. orbital rule: 2, 8, ,8, 18

rows

called periods, tells number of orbitals for elements.

valence electrons

electrons on outermaost shell, iveoved in bonding

why do atoms combine or react

most substances are not individual atoms. but they are compounds. these elements combine to become more stable (full in valance orbital)

lewis dot diagrams

werite chem symble. place one fdot around symbol for each valence. all other electrom are already shown with symbol

atom stabolizarion

most atoms are not stable since their valence is not full. atoms withe full valence are stable, the stable elemts are g 16. atoms will gain, loose ore share electrons to stablize

ions

charged atoms, always in ionic compounds, gained or lost electrons, +ion=cation (metals+hydrogen). -ion=anion

naming ions

positiv ion is same as element, negativ ion ads suffix ide to stem of the name

ionic compounds

compounds of at least one metal and non metal. always solid at room temp. most of the time have high melting points, form crystals (very regular arrangemrnt), disollv in water to form conductive solutions

matter

anything with mass and volume. can be solid, liquid gas or a combination of states

Mass

the measure of the quantity of matter in an object.

Volume

• a measure of how big an object is or how much space a substance takes up. (The unit is liters (L) or milliliters (mL)).

The Particle Theory of Matter.

.. summariz[es] what scientists have learned about the particles that make up matter, the main parts being: All matter is made up of tiny moving particles,Particles attract each other. Particles move faster when heated, differecnt substances have different particles, particles move random constantly

Changing States

In order to change states, you need to heat an object or cool an object.

solids

Particles $\underline{\text{vibrate}}$ but stay in fixed positions. Particles are close together. Solids will not easily change $\underline{\text{shape}}$ or $\underline{\text{volume}}$.

liquid

particles in liquids are close together but are randomly arranged. Particles in liquids slide past each other, creating flow.

gassas

Particles in gases are $\underline{\text{far}}$ apart. Particles move $\underline{\text{very fast}}$. Gases will $\underline{\text{always}}$ fill a way to fill the entire container.

melting

The change from the solid state to the liquid state. The temperature at which it occurs is melting point(also a characteristic property). solid absorbs thermal energy and temp rises

freezing

The change from the liquid state to the solid state is called Freezing. the temp it occurs is freezing point(also a characheristic property), iquid releases thermal energy after all is solid temp begins to decrease

vapourizing or boiling

The change from the liquid state to the gas state, involves the absorption of thermal energy temp does not increase after reaching the point of occurence or boiling point(allso a characteristic property). below surface

Pure substance

matter that has a uniform and definite composition. (always the same proportion of components).A pure substance is either an element or a compound.

evapouration

change of state to gas at surface liquid, occurs at temperatures below the boiling point, speedy molecules rise to surface quick (or are on surface) of liquid escape liquid, changing state to gas

condensation

as a gas cools, particles slow, when slow enough there attractions bring them together to become liquid. opposite of vapourization. loooses thermal energy, gas to liquid.

sublimation and deposition

in right condittions solids and gasses can change state without becoming liquid. sublimation is solid to gas eg. black ice. Deposition is the change in state from a gas directly to a solid: Ex. Frost

property

chrictaristic that discribes a substance

substance classification

may be classified as pure substances or mixtures, depending on how their particles are arranged.

pure substance

Made up of only one kind of particles. is either an elemant or compound

elemant

An element is a pure substance that cannot be broken down into any simpler substance by ordinary chemical means. examples are silver and oxygen.

compound

a pure substance that is made from two or more elements that are chemically joined together in a fixed ratio.

molecules

Two ore more atoms chemically bound not always a compound can be multiple of same eleement. eg. oxygen.

mixture

a combination of two or more substances. however the substances are not chemically combined each remains in original forms even if not easily visible. there are three types.

mechanical mixture

different substances that make up the mixture are visible. these are a type of heterogeneous mixtures. (also called hetrogenous)

suspension mixture

different substances that make up the mixture are visible. in these the suspended substance may settle. also heterogenous

solution

different substances that make up are not individually visible - forming a homogeneous mixture. like sugar in coffee, apple juice

physical property

is a characteristic of a substance that can be observed without changing the substance's identity. examples

qualitative properties

propertity that cannot be measured, observed iwth sences

qualitative property

measurable property, has a numaeical value

examples physical properties

state of mater, mass and volume. optical clarity; how clear an object appears (light it lets through) transparent translucent opaque. solubility ability to disolve. malleabiliy ability to be rooled or hammered(metal). luster/shine amount of light substance reflects(cold). ductility; sbility to be drawn wire. hardness(abi. to resist scratching). brittleness(hw flexibility or how easy it breaks). viscosity (how much liquid resists flow honey vs water). electrical conductivity measure of how wall electric currents move through a substance

Charictarisctic physical properties

unique phyical property specific to a substance used to identify the substance. three common ones are dendity freezing/melting points, boiling point

density

amount of msss per unit of volume. D(g/ml or g/cm3)=mass(g)/v(ml or cm3)

physical change

change in which the composition of the substance remains the same. no new substances are priduced. generally easy to reverse but not always. the three are change in state, change in shape, dissolving(solvent can be evaporated). 

chemical property

a discription of what a substance does when it reacts to form a different substance with new chemical structure. combustibility ability of substance to react with oxygen to produce heat and light energy. flamability ability of substance to burn. oxydation reaction with oxygen to form new substance (iron with oxygen to make rust). corrodibility ability to distroy or damage a substance chemicly.

chemical change

a change that occurs that sauses the identity of substance to change due to somthing new being formed with new properties. chem change is the occurencrthe real action, chem property is the substances ability to uncergo a specific property.

evidinces of chem change

change in colour(not always), bubbling in gas (not always), solid (percipitate) formed from non solids, change in energy(heat or light absorbed). difficult to/ irriversible

atmosphere

layer of gas surrounding earth held by earths gravitational pull. made up of 78% nitrogen, 21% oxygen and one percent others. the atmosphere holds temperature avg at 15c, without avg would be -18c. it also blocks uv and other rays from sun.

lithosphere

earths rocky outer shellconsisting of rocks and mineral that creat mountains, the ocean floor and thr rest of earth land scape. this sphere spans 50-120km in width.

Hydrosphere

all water in all forms above, on or below earth`s surface. it includes lakes and rivers, ice, oceans, groundwater, and clouds. 

biosphere

the locations where life can exist. Majority of species live in ocean, land, and even underground (micro-organisms).

ecology

The study of relationships between living organisms and between organisms and their environment. The ecosystem may be described in different scales, e.g., a pond, a forest, or a meadow.

abiotic

non living parts of ecosystem

biotic

all living things including their waste, things they produce (poop), and their dead or decaying body until fully decomposed in ecosystem.

species

A group of organisms which can interbreed and produce fertile offspring

hypbrid

sterile offspring of individuals related species are interbreed and produce. only possible with related species. e.g., a mule.

population

A group of organisms of the same species that are living in the same area at the same time. 

organisms of the same species that are geographically are of separated are unlikely to breed though they can (they are pf different populations). if there is no interaction between their communities they will eventually develope differences hey are different species until thy cannot produce fertile offspring

community

A group of populations that are living and interacting with one another. All organisms are dependent on interactions with members of other species for survival. they also include plants and microbes.

habitat

The environment in which a species normally lives

ecosystem

a community and its abiotic environment

organic molicules

molecules that carry out life functions like metabolism growth and reproduction

autotrophe

• It is a process where organisms synthesize their own food (organic compounds) from inorganic raw materials (likeco2 and water).

• They capture energy (mostly sunlight) and convert it into chemical energy (food).

• They form the base of all food chains as producers.

hetrotrophe

e organisms that cannot make their own food and must obtain organic molecules, from other organisms. Most heterotrophs do not have chlorophyll and cannot perform photosynthesis. feed on autotrophs and/or other heterotrophs.

mixotrophe

organisms tht can cary out photosynthesis and take neutrientst from ground. Allong with obtaining organic molecules from other organisms.

trends in plant and algae neutrition(paracitic plants algae)

majority of species of plants and algae are autotrophs. some plants and algae Heterotrophs. not making their own organic compounds. they have no chloropaths or photosinthesys. these  are parasitic for they get their organic compounts from plants they grow on,<. only a few of plants and algae fall into this (1%)so they are autotrophes overall

consumers

hetrortoph that injest 0n living organism by injrstion. they can be divided by what they eat

herbivores

feed exclusively on plants and algae. (e.g. deer, zebra and aphids)

Omnivore

feed on a combination of both producers and consumers (e.g. chimpanzee, mouse

carnevore

feed exclusively on animals (e.g. lions, eagles, and ladybirds)

scavenger

specialized carnivores that feed mostly on dead and decayed animals (e.g. hyenas, vultures and worms)

primary consumer

feed on autotrophs

secondary consumer

feed on primary consumers

detritivore

hatromorphs that injest dead organic matter by internal digestion such as dead leaves (humus), other plant parts, carcasses of animal bodies and faeces. they are digested internlly and the product of digestion is absorbed. such as dead leaves, humus, other plant parts, carcasses of animal bodies and faeces

saprotrophe

hetroe trophs that live on dead organic mater. they secrete digestive enzyme onto their food which digestes it and then the absorb the product. unlike others they are not consumers since their digestion is external. they help decompose organic matter  also called decomposers.

ecosysyem sustainability

they maintain a relatively constant set of characteristics over long periods by themself.

continous energy suply (eg sunlight)

neutrient recycking

waste recycling

sustainablity

ability to mentain natural ecological conditions and processes eothout interuption weakening or loss of value

neutrient cycling

supply of neutrients is limited so they are constantly recycled between organisms

autotrophy convert neutrirnts from inorgsnic to orgsnic molicules

hetrotrophs injest other organism to gain organic forms of neutrirnts 

saphotropes break down organic neutrients to gain energy and release neutrients into organic molicules