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# System prepended metadata

title: Finals

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# Geography 
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# Lesson 1 - Human Origins
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- Archaeologists study artifacts and fossils to understand how humans lived in the past.
**==Artifacts==:** objects made by humans in the past
**==Fossils==:** the remains of an organism in the past

*Africa:*
- Earliest human fossils found here (East Africa)
*Lucy:*
- Early hominin
- From ethiopia
- Her bones let archaeologists know that she can walk on legs

*How Early Hunter Gatherers Lived*
- ==Hunter Gatherers== are people who survived by hunting, fishing, and gathering wild plants. 
- Humans developed technology to meet their needs and wants. 
    - For example, in the stone age, people made tools out of stone. Overtime, the tools became thinner and sharper, which was more skillful. They could hunt larger animals with those weapons they made by stones
- During the Paleolithic Era, people also learned how to use ==fire==.
- They have light at night when it's dark and migrate to colder places
- They could cook
    - Food becomes more nutritious and diseases wont spread that easily
- They can scare their predators away
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# Lesson 2 - Ancient Egypt and Kush
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**==Civilization==** - an advanced state of humans society

*Ancient Egypt:*
- Two kingdoms developed in Egypt: Upper and lower Egypt
- A king named Narmer ruled both of the kingdom 
    - He is the first pharaoh, king of the united Egypt
    - He also founded Egypt’s earliest dynasty (ruling family)

 *Egypt’s Society*
- Pharaohs needed the loyalty and labor of the people to control egypt
- The society was supported by many farmers, servants, and slaves, who together did most of the work but had the lowest status. 
- Egyptians believed that gods controlled everything 
- Below pharaoh were nobles, priests and officials. 
    - They helped the pharaohs govern egypt. 
- Scribes also kept records for its ==bureaucracy== (a system of many government officials who carry out government rules)
- Most of the ancient Egypt were farmers
    - Many farmers worked as laborers on the pharaoh’s building projects
- Slaves were at the bottom of the social status
![Screen Shot 2024-01-08 at 10.19.37 PM](https://hackmd.io/_uploads/rJbqNtKOa.png)

*Egyptian’s Religion and Achievements*
- People believed that gods controlled everything from the flooding floor of the Nile River to the death of a child
    - Gods can be kind or dangerous
- They were polytheistic and worship many gods
- Egyptians believed that life on Earth could lead to an afterlife
    - They prepare for the afterlife by having their body preserved after death. 
    - They believed that the spirit would need to recognize their preserved body
- Ancient egypt developed early forms of writing by using ==hieroglyphics== (a drawing or symbol that stands for a word, idea, or sound)
    - They write with ink on ==papyrus== (a paper-like material)
- Science (mummification) and Mathematics (Pyramids) 
    - The ability to construct the great pyramids proves their command of their knowledge and their engineering concepts
    - They used irrigation and had a surplus of crops, so farmers became rich and rulers.	
    - Ex: Geometry, Engineering, Irrigation, Astronomy, Medicine, Chemistry


*Kush:*
- Rich in resources, including golds
- To gain and control over these riches, Ancient Egypt attacked the Kushite civilization
    - Egyptians want the gold and resources, So they conquered the Kush and forced them to pay a tribute (money that signifies dependence)
    
Sequence Events: ==Egypt conquered most of Kush during the Middle and New Kingdoms. When Egypt weakened after the new kingdom, Kush became independent. Later, a Kushite king conquered the Egyptian city of Thebes. The next Kushite king conquered the rest of Egypt and united the two lands.==
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# Lesson 3 - Later African Civilizations
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***Western Trading Empires***
- Ancient Egypt’s food surpluses had helped the population grew
- They allowed civilization to develop 
- ***==The Kingdom of Ghana==***
    - It's the first great empire
    - Founded between the Niger and Senegal rivers
    - Good at making iron weapons and helped them conquer people
    - ***==Gold-Salt trade==***
        - 7th-14th century
        - Mediterranean countries needed gold
        - Sub-Saharan countries needed salt (important for human diet)
        - Kingdom of Ghana took advantage of this trade and taxed the people who crossed the borders of Ghana to trade

- ==The Empire of Mail==
    - Mali’s greatest empire, Mansa Musa, ruled from 1312-1337
        - Practiced Islam
    - Made a religious journey to the Arabian city of Mecca

- ==The Songhai Empire==
* 1400s Songhai took over Mail, and became the largest empire in Africa 
* Some people lived in Slavery
* Enslaved people were mostly farmworkers who had some legal rights and protections
* 1500s, competitions between rulers had weakened Songhai
* Soldiers from North America invaded and defeated the empire
* 1600s, Songhai had split into smaller states 


***Axum and Ethiopia***
* The kingdom of Axum replaced Kush as the commercial hub
* Located in ethiopia which helps them make Axum a center for trade
    * Golds, ivory, textiles, tools, jewelry, steels……
* Axum’s wealth and power led to altars honoring gods
* ==Axum slowly weakened in 600s due to economic problems and the spread of Islam==
* Zagwe rose to power and continued christian traditions 
* They promote their religion and ==traded successfully with Muslim world ==

***East African City-States***
* Trade connected East Africa, the Mediterranean, and India brought distinct people together
* 800s ~ 1400s: Muslim immigrants came to coastal East Africa
    * Mixture culture
* Swahili culture
    * Formed in a trading town
    * Imported ceramics, glassware, silk, and silver and copper
    * Adopted Islam
* ==Coastal settlement → city-states, centered on Stone Town==

***Bantu Peoples in Southern Africa***
* About 1000 BCE: The population of the first Bantu people grew → Land couldn’t accommodate them → They migrated into East and Central Africa
* 1 CE: Spread into Southern Africa
    * Introduced farming method
    * Brought skills in making iron tools
* Great Zimbabwe thrived in the 1400s.
    * Great Zimbabwe’s traders took gold and ivory
* No ethnic majority
    * ==Ethnic groups=====a shared identity and cultural traits==
    * Some share a common religious
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# Lesson 4 - Colonization and independence in Africa
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==Imperialism== - country policy to take over lands using diplomacy or force
==Colonialism== - the physical act of setting up colonies or territories in another country

***European Rules***
* Africans began trading with Europeans who had recently arrived on their coastlines
* Gold drew european to africa 
* Europeans began involved in slave-trade
* They would control most of the continent later on

***Atlantic Slave Trade***
* Europeans greatly increased the impact of the slave trade on Africa
* African traders sell enslaved people for guns and other goods
* Europeans then brought enslaved Africans across the Atlantic Ocean to work
    * It involved more than 13 million enslaved people
    * Hundreds of thousands people died during the journey
* ==With European guns, slave-trading states could defeat neighboring people and capture even more slaves to sell, creating an arm race==

***Europeans Take Over Place:  ***
* European countries were interested in taking over Africa because ==Africa had the resources that they needed.==
* Europeans were able to take over Africa because ==they had superior weapons then the Africans.==
* Religion reasons behind colonization: The Europeans ==wanted to spread Christianity and even forced some of the Africans to convert.==

***Impact of Colonialism ***
* By 1900, European nations had colonized much of Africa, except for ==Ethiopia==, which ==faced an Italian invasion== in the 1930s. 
* ==Colonization led to hardships== for Africans, including ==land loss== and ==forced labor==. 
* Resistance efforts were hindered by superior European weaponry. 
* Despite challenges, Europeans introduced positive changes like abolishing slavery, improving healthcare, enhancing transportation for resource export, and establishing schools for African education.


***Independence***
* ==Africans had little/no control over the government==
    * Grew frustrated
    * Kwame Nkrumah
    * Political leader
    * ==Pan-Africanism== - ==a political and social movement to unite black Africans around the world==
        * influenced other political leaders
        * Kenya also gained independence
        * Ghana gained independence in 1957

***After Independence***
* ==Congo==
    * Been given independence by Belgium in 1960
    * Joseph Mobutu 
        * Seized control
        * Changed the name to Zaire
        * Ruled for 32 years

* ==Nigeria==
    * Ethnic discord
    * oil-rich region left Nigeria
        * Form Republic of Biafra
        * Civil war
        * Many people in Biafra rejoined Nigeria

* ==South Africa==
    * Gained independence from Britain in 1910
    * White people kept political & economic power
    * Adopted apartheid in 1948
        * Apartheid - former South African policy of strict separation of races
        * Restricted black people’s freedom → protest
        * African National Congress (ANC) fight for black people’s right
        * Nelson Mandela
            * ANC leader
            * jailed in 1962
            * became president

* ==Sudan==
    * ==North Sudan==
        * Now still call Sudan
        * Most are Arabs (Islam)
        * Gained independence in 1956

    * ==South Sudan==
        * Belongs to other ethnic groups
        * Not Muslim
        * Gained independence in 2011

    * ==Darfur==
        * Region in west of Sudan
        * Most Black farmers were killed
        * Genocide - An attempt to destroy whole people.

    * ==Rwanda==
        * Divided between two main ethnic group
        * Hutu and Tutsi
        * Belgium colonized region, Tutsi ruled Hutu → independence → Hutu ruled Tutsi
        * Genocide → Hutu military killed Tutsis → Tutsis hold power → Violence stopped → Hutus moved to Zaire (Democratic Republic of the Congo)
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# Lesson 5 - Living in Africa 
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***Where Africans Live***
* Africa is the second largest continent 
* ==Geography and climate help determine population density in Africa==

***Settlement Pattern***
* Many populated regions in africa are found near sources of water or in climate with regular precipitation 
* ==Population is most highly dense in Mediterranean sea and nile river valley==
* Regions of africa with a tropical wet climate do not typically have large populations
* rainforest s that grow in these areas are dense and soils are poor

***The Importance of Water***
* Many of africa’s cities have developed around harbors or rivers that made it possible to transport goods from africa’s interior to the rest of the world
* People may move to cities to look for work because a season’s crops have failed. 

***The Sahara’s great Divide***
* Drier regions of Africa are much more sparsely populated 
* Very few people live there
* Many of these people live and farm in oases
* An ==oasis== is a ==place in the desert where water can be found==

***Environment and Culture***
* Different cultures have developed in different environments 
    * North africa cultures developed in the mild climate with its rainy winter season
    * In Sahara, people created very different cultures to adapt to the dry desert climate
    * People in the forests and savannas, park-like grasslands with scattered trees that can survive dry spells, developed cultures adapted to those environment 
    * Irrigation brought water to dry land, but te grazing of livestock stressed grassland prone to drought 

***Religion and Ethnicity***
* Geographic features, cultural ideas and practices will affect the culture

***Religious Diversity***
* ==Islam== is dominant religion in the ==north, east, and northern parts of africa==
* Egypt has a large ==christianity minority== called ==copts== (speak arabic)
* ==Kenya and tanzania== are mainly ==muslim==
* ==East africa== are mainly ==christianity==
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# Lesson 6 - Africa at work: 
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* Most countries in Africa today are corrupt and there is only 1 that is full democracy (Mauritius)
* Citizens cannot protest in these African corrupt countries and the governments typically don’t function well. 
* The people are faced with violence but they can do nothing about it.
* The US and other European countries threatened to stop providing aid to African countries if they didn't stop their unjust violence, but it had no effect. And LGBTQ people still face violence in Africa.
* The people in Africa have a low standard of living and there are usually autocrats leading those corrupt governments.
![Screen Shot 2024-01-09 at 11.25.29 AM](https://hackmd.io/_uploads/B1PAnE5_a.png)
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# Lesson 7 - Challenges Facing Africa
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***Environmental Challenges***
- Africa struggles with ==serious environmental problems==
    - Access to clean water
    - Diseases 
    - Loss of trees
    - Frequent droughts
***Clean Water***
- Africans ==do not have access to toilets or waste disposal==
    - ==Human waste== often ==ends up in river or underground water== that ==people use for DRINKING== 
    - ==Cholera== is a kind of disease that spread quickly and can ==kill people==
        - 115 ==africans died per hour== from ==water pollution==

***Deforestation and Desertification***
* ==Deforestation== is the loss of forest cover that results from so ==many trees being removed that trees cannot grow back==
* When too many trees are cleared, nutrients in the soil wash away with the rain
* ==Desertification== is ==the change from arable land to desert==
    * It is a major problem in ==sahel==

***Droughts***
* Climate change may contribute to the increasing droughts
* Many people died from droughts resulting famine
* Half of them was age under 5 
* It brings harder life to people

***Political Challenges***
* Many africans countries became more democratic in the 1990s
* Rulers block opposite and hold onto power

***What Holds Africa’s Economies Back?***
* Many africans ==do not receive proper education== or ==decent health care==
* As a result they are ==not as productive==
* ==Political conflicts== hurt africa economies

***Infrastructure***
* Africa faces challenges of a ==poor transportation infrastructure==
* Roads are not sufficient for getting goods to market
* Half of all africans live in areas without tarred or paved roads











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# Physics
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# Week 10 - The periodic table
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==Pure substance==:a material that cannot be seperated into its parts

| Element | Atomic Number | Atomic mass - number of protons |
| -------- | -------- | -------- |
| things on the periodic table     | Number of Protons     | number of neutrons     |

-Atoms are divisible
-Periods = across
-Group = down (have similar properties)
-Periodic table
- left = metals
- right = non-metal

-Ions = positively charged atoms
-Cations = negatively charged atoms
-Metals tend to form ions by getting rid of electrons to make their valence shell stable
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# Week 11 - Extended structures
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-Number of Protons=changes the identity of the atom
-Number of Neutron=affects the stability of an atom but not its chemical properties
-Number of Electrons=affects the charge of the atom
-==Valence electrons===the electrons on the ==outer most shell== (valence shell)
-number of electrons on each valence shell=2, 8, 8, 18, 18, 32, 32
### Types of Bonds:
- ==Ionic Bond==
    -    ==metal and non-metal==
    -    The metal, with 1 extra electron, will donate that electron to the non-metal, making both of the atoms stable
    -    The metal will become cation (positve), since it got rid of an electon
    -    The non-metal becomes a anion(negative), since it gained 
- ==covalent bond==
    - ==2 non-metals==
    - 2 atoms share more than 1 or more pairs of electrons
- ==metallic bond==
    - ==many metal atoms together==
    - many electrons detached

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# Week 12 - Structure of Matter
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==Molecules==: 
- two or more ==atoms held together by chemical bonds==, ==attractive forces== that ==hold atoms together==. 
- smallest particle of a substance that still has all the chemical properties of that substance. 
==Compound==:
- ==a molecule== made up of two or more ==different types of atoms joined by chemical bonds==
- Can be broken down chemically into smaller substances or elements
==Pure Substance==:
- made up of ==only 1 type of matter==
    - a "mixture" contains ==two or more different types of pure substance==
==Chemical bonds==:
- A chemical bond is ==not a physical thing==; It is the ==attractive force== that holds atoms together. These bonds ==may be visible when we model molecules. ==
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# Week 14 - Chemical Processes and Equations
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Writing Chemical Formula
- If the compound is made of a ==metal element and a nonmetal element==, then the ==metal element is first.== 
- If there are ==two nonmetal elements==, then the ==first name== is the ==element to the left side== of the periodic table. 
- If the elements are in the same group, the first name is the element at the bottom of the periodic table. 
Naming Compounds
![Screen Shot 2024-01-08 at 8.36.29 PM](https://hackmd.io/_uploads/HyCD3vtda.png)
Covalent Compund 
- ==Covalent compounds== are made when ==two or more elements share electrons in a covalent bond to connect the elements. ==
- Covalent compounds follow a different naming scheme.

| CO | CO2 | N2O4 |
| -------- | -------- | -------- |
| carbon "mono""xide"    | carbon "di""oxide"    | "di"nitrogen "tetra""oxide"     |

Changes of Matter
- Changes to substances take place all around you every day.
- Changes such as water freezing or metal being hammered into a thinner sheet do not alter the identity of the substance. 
- Changes such as milk spoiling or silver tarnishing do change the identity of substances.

==Physical Change==
- When a physical change takes place, the identity of a substance remains the same after the physical change. 
- The particles that make up the substance are the same before and after the physical change. 
- ==Physical changes only change the appearance of the substance. ==

==Chemical Change== (Chemical. Reaction)
- When substances are mixed together, a chemical reaction may or may not take place. 
- When a chemical change does take place, the original substance changes into a different substance with different properties. 
- A chemical reaction is ==the process in which atoms and bonds are rearranged to produce different substances==
- The ==new particles== could be ==atoms or molecules==

Determine Ionic Bond or Covalent?
- Ionic: Metal to Non-metal
- Covalent: Non-Metal to Non-Metal
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# Week 15 - Writing chemical equations
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Chemical Reaction
- Any change that ==produces a new substances==
- the bonds in the reactants break apart and re-form into new substances, the products
- The products have properties that are different from the reactants because the molecules that make up the products are different from those in the reactants. 

Chemical Equations
- A chemical equation uses chemical formulas to model what happens in a chemical reaction. It shows how the reactants change and form the products of the reaction. 
- One or more chemical formulas are shown (reactants), separated by addition signs. 
- The formulas are followed by an arrow pointing to the right, then one or more different chemical formulas are shown (products). 

Types of Reaciton
- ==synthesis reaction==
    - a reactants interact and form onw product
    - A+B--> AB
    - Example:Na+Cl=NaCl
- ==Decomposition Reaction==
    - A compound breaks down into atoms
    - AB--> A+B
    - CaCO³= CaO+CO²
- ==Combustion ==
    - when a substance react with oxygen form fire 
    - chemical reaction between substances
    - Example: CH⁴+2O²= CO²+2H²O
- ==Single Replacement Reaction==
    - a reaction that occurs when a new compound is formed when one element is subtituted for another element in a compound creating a new element and a new compound as product
    - AB+C=AC+B
    - Example: SnCl²+Zn=ZnCl²+Sn
- ==Double replacement==
    - A reaction in which the cationic or anionic species switch places, creating two new products
    - AB+CD=AC+BD
    - Example: KCl+AgNO³=KNO³+AgCl
- ==Neutralization (Acid Based Reaction)==
    - A doube replacement in which an acid reacts with a base to form water and salt
    - Example: HCl+NaOH=NaCl+H²O
- ==Precipitation Reaction==
    - a double replacement reaction in which forms a solid from two miscrible liquids
    - Example: AgNO³+KCl=AgCl+KNO³
    
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# Week 16 - energy and chemical process
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Indicators of chemical change
- Color
- odor
- energy change (temperature, thermal energy)
- precipitate formation (2 soluble salts combine together to form 2 products)
- formation of bubbles

==Exothermic vs. Endothermic==
- exo===release heat==
    - causes the temperature of the surrounding to heat up
    - freezing water
- endo===absorb heat==
    - cause the temperature of the surroudning to cool down
    - melting ice cream
![image](https://hackmd.io/_uploads/Sy-Z3a5uT.png)
![image](https://hackmd.io/_uploads/By4QhT9d6.png)
### How to increase rate of reaction?
- increase temperature
- increase reaction concentration
- increase surface area of the reatants
- add a catalyst

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# Week 19 - Pressure and changes of state
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Pressure:
- ==the force exerted on the container by the particles==
- caused by particles colliding
- pressure = force/area
- ==higher elevation = lower pressure = lower boiling point==
    - because less energy is needed to boil
- ==lower elevation = higher pressure = higher boiling point==
    - more energy needed to boil

Factors affecting pressure
- increase the force that is applied
- decrease the area
- increase the temperature (particles move faster with more kinetic energy, so they would collide more often)
- increase the size of the particles
- add more particles

### Phase change
![image](https://hackmd.io/_uploads/HkytJRqO6.png)
In a plasma, electrons are ripped away from their nucleus, forming an electron “sea”. This gives it the ability to conduct electricity.

Freezing point:
- ==higher== freezing = ==easier== to freeze
- ==lower== freezing = ==harder== to freeze
- salt can lower freezing point
    - so countries spray salt on frozen sidewalks to melt them easier