Science

In this lesson... 

- Science
- Scientific Method 

Science: 

●  The ​study of the physical and natural world through observations and experiments
●  Includes ​biology ​(studies of organisms: all life on Earth),​ chemistry​ (studies of the properties of substances: chemicals, air), and ​physics ​(studies of the physical world and how it works: motion, magnetism)
 

Scientific Method: 

1. Ask a question 

1. Find a problem regarding the science field 
2. e.g.- What is the effect of acids on mold growth? 
3. Always write a question about the effect of something on another
    

2. Do background research 

1. For accurate scientific information, ​look for scholarly and peer review sources for your information. 
2. Your school may pay for a service that gives you access to peer reviewed papers, such as jstor. You can also look at google scholar, but getting access to scientific journals is best.

3. Come up with your hypothesis 

1. Your hypothesis is your prediction of what the results will be 
2. If ​blank happens​, then ​blank will happen.
                                       Or
3.  If ​blank happens​, then ​blank will happen​, because ​blank d. If...Then...Because 

4. Test your hypothesis with an experiment 

1. You will have to design and then carry out your experiment 
2. It is up to you to figure out how to test your hypothesis 

5. Analyze data 

1. You will have to analyze the data with graphs and charts 
2. You should also identify any errors you may have made in your study that may have affected your results 

6. Report your data (was your hypothesis right or wrong?) 

1. Figure out if your results proved or rejected your hypothesis. If neither happened, your results are inconclusive. 
2. You should also think about future studies you can do to improve upon your results.
    

Independent Variables: (Manipulated Variable) 

● The variable that is changed by the experimenter and causes other variables to change. 

     ○ Example: If you were testing the effect of different acids on the growth of plants, you would use x amount of acids to see the effects of each one of them. 

         ■ Each of the different acids you use is an independent variable 

Dependent Variables: (Responding Variable) 

● The variable that changes as a result of the independent variable changing.
   ○ Example: If you were testing the effect of different acids on the growth of plants, you would use x amount of plants to see the effects of each acid on each plant.
       ■ The plants growth, which changes as a result of the change in type of acid, would be the dependent variable 

Control Variable 

● The variable that is used as a reference to the changes in the independent and dependent variable. 

     ○ Example: If you were testing the effect of different acids on the growth of plants, you would need to test one batch of plants with water. 

         ■ You would use water as a control variable because the acids will cause the plants to grow many different sizes and since you want to see the effect of them, you need to compare the growth to the growth of a regularly watered plant 

Constants: 

● Parts of the experiment that stay the same
○ Example: If you were testing the effect of different acids on the growth of plants, variables such as sunlight, amount of acid, and type of plant would be the same. 

• These would be the same because you want your results to be as real, true,
  and credible as possible. 
• If you didn’t give each plant the same amount of sunlight, you don’t know
  that the plant didn’t grow because of the acid and not the lack of sunlight.
   

In this lesson... 

-  Weather
-  Atmosphere
-  Climate
-  Natural Disasters
-  Greenhouse Effect
-  Weathering
-  Water Cycle
 

Weather: 

●  The ​state of the atmosphere
●  Describes the ​temperature (hot or cold)​, ​humidity (wet or dry)​, or ​current water state of the atmosphere
●  Takes ​place in the troposphere
   

Atmosphere:
● 5 layers of the atmosphere: 

     ○ Troposphere 

• Around ​10 km/6 mi above the ground​ (Earth) 
• It contains nearly all of the water vapor in the atmosphere: why all the clouds are there 
• Tropopause (top of troposphere): temperature stops decreasing from  -60°F / -15°C 

      ○Stratosphere 

• Begins above the troposphere and extends ​50 km/31 miles above the ground​ (Earth) 
• Temperature goes up from what is was in the troposphere and stops as it reaches freezing point (starts increasing from -60°F / -15°C) 
• Fairly calm section of the atmosphere
  ●  Not a lot of convectional air movement
  ●  Causes pollutants to remain in this region for a while, but...
  ●  The ozone layer is here and it helps protect us from the sun 

     ○ Mesosphere 

• Begins above the stratosphere and extends ​85 km/53 mi above the ground​ (Earth) 
• We don’t know a lot about it because it is too high for aircrafts/weather balloons. 
• Satellites aren’t helpful either because they can only see the mesosphere from above the atmosphere. 
• Meteors that would, without the mesosphere, hit the earth, are usually vaporized here, give it a higher concentration of metals. 

      ○ Thermosphere 

• Begins above the mesosphere and extends ​500-1000 km/311-621 mi above the ground​ (Earth) 
• Part of the atmosphere where space is considered to have begun 
• Has extreme temperatures 
• Most satellites are present here 
• Home to the Aurora Borealis 

     ○ Exosphere 

• Almost identical to space 
• Not a lot going on 
• International Space Station orbit below the exosphere 
• Some scientists ​consider it not a part of the atmosphere 

Climate: 

●  5 main climate types
   ○ Tropical 

• Hot and humid 
• Average temperatures are greater than ​64°F / 18°C year round 
• Over 59 inches of precipitation per year 

     ○ Dry 

• Moisture evaporates quickly 
• Very little precipitation 

     ○ Temperate 

• Summers are warm and humid 
• Have thunderstorms and mild winters 

      ○ Continental 

• Warm to cool summers 
• Very cold winters 
• During the winters, there could be snowstorms, strong winds, and very cold temperatures 
• Can go below -22°F / -30°C 

       ○ Polar 

• Very​ cold 
• In the summer, ​temperatures don’t rise above 50°F / 10°C

 ●  The ​climates of the Earth resemble a rainbow
      ○ The rainbow begins at the equator with tropical climate, then goes to dry, then temperate, continental, and polar. 

**Climate map can be found in the PDF version of the notes above (Derived from wikimedia commons) **

Natural Disasters:
● 10 main natural disasters: 

     ○  Earthquakes​ - Unusual movement in the Earth’s crust: the causes the ground to shake
     ○  Landslides/Mudslides​ - Parts of mountains collapsing/ Water accumulates in the ground and mixes with dirt of a slope
     ○  Volcanoes​ - Magma in the Earth’s crust explodes
     ○  Extreme Heat​ - Temperatures rise above 130°F / 54°C
     ○  Lightning​ - Sparks of electricity in the atmosphere
     ○  Wildfires​ - Small sparks of electricity, or the sun causing a fire to spread rapidly
     ○  Floods ​- Extreme accumulation of water
     ○  Tornadoes​ - Warm, human air hits cold, dry air
     ○  Winter Weather​ - Blizzard, snow
     ○  Hurricanes​ - Extreme thunderstorm
     ○  Tsunamis​ - Extreme tidal waves
 

Greenhouse Effect: 

● The ​sun’s heat gets trapped in the lower part of the earth’s atmosphere ​which warms the planet above what it would be 

     ○ Global Warming 

Weathering:
● The ​weather breaks down things on the Earth by the atmosphere and water 

      ○ Rocks, soil, minerals, wood, and artificial materials 

Water Cycle: 

** Image of the water cycle found in PDF version above (Derived from Wikimedia Commons)**

In this lesson... 

-  Space
-  Big Bang Theory
-  Solar System
-  Eclipses
-  Tides
-  Comets/Asteroids
 

Space: 

●  Outer Space
●  The ​world that exists beyond the one we live in​ (Earth)
●  Consists of ​low density, particles, radiation, magnetic fields, and cosmic rays
 

Big Bang Theory:
●  The leading explanation of ​how the universe came to be
●  Everything ​started out small and then expanded to almost what it is today in a fraction of a second
●  This all began around ​13.8 billion years ago 

Solar System: 

●  System in which ​objects in space orbit around the sun
●  We are on Earth, which is a planet, which is part of a galaxy (Milky Way), which is part of a universe, which is part of etc. 

●  Sun: 

     ○  The star at the​ center of our solar system
    ○  It is an almost ​perfect sphere of hot plasma
    ○  It has a ​magnetic field around it
    ○  It is the ​most important energy source in the solar system 

●  Moon:
    ○  The moon is a ​natural satellite to the earth
    ○  Many​ other planets besides earth have moons
    ○  The moon is​ made of oxygen, silicon, magnesium, iron, calcium, and aluminum
    ○  You can see the moon glowing almost every night (not when there is a “new moon”). The moon does not actually provide light itself, the glow of the moon is the sun shining through.
    ○  Humans have visited the moon, the first one to successfully reach the moon was Neil Armstrong in 1969
    ○  The moon has phases: Image on PDF version of notes above!

● Planets: 

     ○  Our solar system has planets: ​a large object in the solar system, possibly with life on it (Like Earth!)
    ○  There are ​8 planets that orbit around the sun​.
    ○  A mnemonic you can use to remember the planet’s names and their order from closest to farthest from the sun is:
         ■ My Very Educated Mother Just Served Us Nine Pizzas 

               ○  The order of the planets closest to the Sun to farthest is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and finally Neptune.
              ○  The largest planet in the solar system is Jupiter, then Saturn, Uranus, Neptune,  Earth, Venus, Mars with the smallest being Mercury.
      ○  Pluto used to be the farthest and most smallest planet in our solar system, but then it was disregarded as a planet later by scientists 

● Stars:
     ○  Object in space that is a luminous spheroid held together by gravity
     ○  Shines because of thermonuclear (hot nuclear) fusion of hydrogen and its helium center
     ○  Stars are a ​part of a constellation​ (group of stars)
     ○  There are about ​1,000,000,000,000,000,000,000 stars in space! 

Eclipses: 

●  Solar Eclipse:
    ○  When part of the Earth has a shadow of the moon in front of the sun cast upon it
    ○  Everything on earth is dark
    ○  Sun, Moon, and Earth align together
●  Lunar Eclipse:
     ○  When the moon appears orange from Earth
     ○  The sun’s light through the Earth reaches the moon, causing it to have an orange color as the moon moves closer to the Earth’s shadow 

Tides: 

●  The ​rise and fall of sea levels
●  Tides happen because of gravitational pull from the moon and sun, and the rotation of the earth
●  They can be ​high and low
●  When you go to the beach you can see this in action. You might arrive at the beach during low tide, but if you look at the sand, you can see the mark where the high tide ended. 

Comets/Asteroids: 

●  Comets are made of frozen gasses, rocks, and dust
●  When frozen, they are the size of small towns
●  They orbit the sun
●  When comets come close to the sun, they heat up and start producing dust and gasses that form a glowing head that is larger than most planets
●  Most comets can only be seen with a telescope
●  Asteroids are minor planets of the solar system
●  Rocky, airless remnants of the early formation of the solar system nearly 4.6 billion years ago
●  Orbit the sun between Mars and Jupiter: Asteroid Belt 

**To view images, please view the PDF version of the notes above.**

In this lesson... 

-  Cells
-  Cell Specialization
-  Animal Cells
-  Plant Cells
-  Mitosis/Meiosis
-  Metabolism
-  Active & Passive Transport
-  Cellular Respiration
-  Photosynthesis
 

Cells: 

●  The ​basic unit of all known organisms
●  Structural, functional, and biological.
●  Smallest unit of life
●  “The building blocks of life”

Cell Specialization:
●  In each part of the body there is a different type of cell
●  There are ​100 types of cells​, but these are the ​11 most common​:
    ○  Stem cells (immune system)
    ○  Bone cells
    ○  Blood cells (there are red and white blood cells)
    ○  Muscle cells
    ○  Fat cells
    ○  Skin cells
    ○  Nerve cells (nervous system)
    ○  Endothelial cells (organs)
    ○  Sex cells (reproduction)
    ○  Pancreatic cells
    ○  Cancer cells 

Animal Cells: 

●  Eukaryotic cell
●  Parts of this cell:
    ○  Cell membrane 

• Controls what comes in and out of the cell 
• Outer Layer 

    ○  Nucleus

• Has a round shape 
• Surrounded by the organelles 
• Controls the cell’s activities 

    ○  Cytoplasm 

• Clear, gel-like fluid 
• Surrounds all organelles 

    ○  Mitochondria 

• Bean shaped 
• Has inner membrane 
• Breaks down sugar molecules to create energy 

     ○  Endoplasmic reticulum 

• Network of folded tubes or membranes 
• Carries proteins and other materials from one part of the cell to another 
• There is a smooth and a rough ER 

     ○  Ribosomes 

• Small bodies floating free or attached to the rough ER 
• Produce proteins 

    ○  Golgi bodies 

• Flattened sacs or tubes 
• Receives proteins or other materials from the ER, packages them, and redistributes them

    ○  Vacuoles 

• Fluid filled sacs 
• Storage area for cells 

     ○  Lysosomes 

• Small, round structures 
• Use chemicals to break down large food molecules into smaller ones 
• breaks down old cells 

Plant Cells: 

●  Eukaryotic cell
●  Parts of this cell:
    ○  Cell wall 

• Outer layer 
• Rigid, strong, stiff 
• Non-living 
• Protects and supports the cell 

     ○  Cell membrane 

• Controls what comes in and out of the cell 
• Outer Layer 

     ○  Nucleus 

• Has a round shape 
• Surrounded by the organelles 
• Controls the cell’s activities 

     ○  Cytoplasm 

• Clear, gel-like fluid 
• Surrounds all organelles 

     ○  Mitochondria 

• Bean shaped 
• Has inner membrane 
• Breaks down sugar molecules to create energy 

    ○  Endoplasmic reticulum 

• Network of folded tubes or membranes 
• Carries proteins and other materials from one part of the cell to another 
• There is a smooth and a rough ER 

     ○  Ribosomes 

• Small bodies floating free or attached to the rough ER 
• Produce proteins 

     ○  Golgi bodies 

• Flattened sacs or tubes 
• Receives proteins or other materials from the ER, packages them, and redistributes them 

     ○  Vacuoles 

• Fluid filled sacs 
• Storage area for cells 

     ○  Chloroplasts 

• Green oval structures
• Usually containing chlorophyll
• Allow photosynthesis to occur

Mitosis/Meiosis: 

Mitosis 

Prophase:​ Chromatin begins condensing into chromosomes. The chromatids are joined together by a centromere. 

Metaphase:​ the chromosomes line up in the middle of the cell.
Anaphase:​ chromosomes break at the centromere and sister chromatids move to opposite ends of the cell. 

Telophase:​ A nuclear membrane forms and chromosomes begin to unwind and separate. 

Cytokinesis:​ The cytoplasm divides and forms two new cells. 

Meiosis is the same thing, but it just ​happens one more time​, resulting in ​four daughter cells instead of two. 

Metabolism: 

●  Metabolism is chemical reactions in organisms that maintains life
●  There are three types
     ○  Carbo types 

• people who have weak appetites and a high tolerance for sweets 
• Weight problems 
• Depend on caffeine 

     ○  Protein types 

• Very hungry 
• Crave unhealthy food 
• Tend towards fatigue, anxiety, and nervousness 
• Feel lethargic 

     ○  Mixed types 

• Average appetites 
• Craving for sweet and starchy food 
• Little trouble with weight control
   

Active & Passive Transport:
Active transport:
●  Active transport describes the moving of materials through the cell membrane
●  3 types 

     ○ Sodium-Potassium Pump
        ■ Cell membrane uses ATP (energy) to transport sodium and potassium ions in and out of the cell 

     ○  Endocytosis 

• Cells take in large particles and deposit them into the cell 
• Ex: taking in glucose 

     ○  Exocytosis
         ■ Deposits materials from inside the cell on the outside ● Transporting materials without using energy 

Passive transport
● Ex: Osmosis: moves water through a cell’s membrane 

Cellular Respiration: 

●  Metabolic reactions and processes that take place to convert chemical energy from oxygen molecules or nutrients into ATP (Adenosine Triphosphate)
●  Releases waste products
 

Photosynthesis:
●  Plants and other organisms use light energy from the sun and convert it into chemical energy that is used to fuel the organism.
●  Carbon dioxide goes in, oxygen comes out.
 

 **To view images, please use the PDF version of the notes above.**    

In this lesson... 

-  Human Body
-  Organs
-  Muscles
-  Bones
-  Hair/Nails
-  Hormones
 

Human Body: 

● Build of a human 

Organs: 

● There are 9 organs: 

     ○ Brain 

         ■ Control system of all of our actions and thoughts (physical and mental) ○ Lungs 

         ■ The lungs release inhaled oxygen into the bloodstream and help exhale carbon dioxide 

     ○  Liver 

• Makes sure blood composition stays the same 
• Breaks down fats 
• Creates urea 
• Filters harmful substances while maintaining the right amount of glucose in your bloodstream 

     ○  Bladder 

          ■ Stretches to store urine and contracts to release urine 

     ○  Kidney 

• Maintains the human body’s chemical balance by getting rid of waste products in the form of urine and feces 
• You can donate one of your kidneys, and you don’t need them both 

      ○  Heart 

          ■ Pumps blood throughout the body in repeated contractions 

     ○ Stomach 

         ■ Breaks down and digests food that you eat 

     ○ Large intestine 

         ■ Absorbs water and waste 

     ○ Small intestine 

         ■ Absorbs food 

Muscles: 

 ●  The muscles, or the muscular system, control the movement of the human body while maintaining posture and circulating blood
●  There are ​700​ named muscles that make up about half a person’s body weight
●  Muscles are made of muscle tissue, blood vessels, tendons, and nerves. 

Bones: 

●  The ​internal frame of the human body
●  A person has ​270​ bones at birth and that decreases to ​206 ​by adulthood, because some bones get fused together
●  Bone mass reaches the maximum density when approaching adulthood

Hair/Nails:
●  Hair and nails are ​types of skin
●  Your hair is dead
●  Hair and nails are both made of keratin, a tough protective protein
 

Hormones:
●  Types of chemicals that are transported in your bloodstream to target organs and regulate behavior
●  There are​ 50​ hormones 

In this lesson... 

-  Chemical Equations
-  Balancing Chemical Equations
 

Chemical Equations:
●  Chemical equations are the ​symbolic equations of a chemical reaction
●  Reactant(s)​ → Product(s)
●  Can have element(s) or compound(s) in the reactant or product
 

Balancing Chemical Equations:
● Chemical equations need to be balanced because each side needs to have the same amount of atoms in each element. 

Equation:  ​NaBr+​Cl​2​ →NaCl+​Br​2 

Step 1: Rewrite the equation, then write the amount of atoms of each of the elements in a chart below. 

NaBr + ​Cl​2​ → NaCl + ​Br​2 

Na = 1 →1        Cl = 2 → 1        Br = 1 →2 

         -  The amount of atoms is shown through the subscript (exponent at the bottom) next to the element abbreviations.
        -  If there is no subscript for an element, its atom value is 1.
        -  If two abbreviations are next to each other with no plus or space, they are a compound of two elements each with a subscript of 1. 

● Writing down the number of atoms in each element helps you to recognize the amount of atoms needed to a certain element in order to properly balance them. 

Step 2: Find which element(s) need(s) to be modified. You need to balance the equation, so both sides need to have elements that have the same amount of atoms. 

Na​Br​ + ​Cl​2​ → Na​Cl​ + ​Br​2 

Na = 1 →1      Cl. = 2 → 1      Br = 1 →2 

         - Sodium doesn’t need to be changed, because it has 1 atom on each side of the equation.
        - Chlorine needs to be modified on the right side because both sides need 2 atoms of chlorine 

         - Bromine needs to be modified on the left side because both sides need 2 atoms of bromine 

         -  NOTE: YOU CANNOT CHANGE THE ATOM COUNT FOR ONE ELEMENT PART OF A COMPOUND!!!
        -  In this example, that means, if you want to multiply the NaBr by 2 to make it equal to the Bromine on the other side, you have to multiply the Sodium too, because they are part of the same compound.
 

Step 3: Balance the equation! You need to multiply certain parts of the equation so both sides are equal.
NaBr + ​Cl​2​ → NaCl + ​Br​2
Na= 1 →1    Cl= 2 → 1      Br= 1 →2 

                         so...
2NaBr + ​Cl​2​ → 2NaCl + ​Br​2
Na= 1x2 →1x2          Cl= 2→ 1x2       Br= 1x2 →2 

           - NOTE: When balancing equations, make sure to put the amount you are multiplying the element or compound by in front of the said element or compound, NOT in the subscript. 

●  You needed to multiply Chlorine on the right side by 2 and Bromine on the left side by 2.
●  Since they are part of a compound with Sodium, you also need to multiply the Sodium on each side by 2 as well.
 

Step 4: Check the equation! Make sure the atoms in each element on both sides of the equation are the same. 

2NaBr + ​Cl​2​ → 2NaCl + ​Br​2 

Na= 2 →2       Cl= 2→ 2        Br= 2 →2 

● Each element has 2 atoms, so the equation ​2NaBr + ​Cl​2​ → 2NaCl + ​Br​2 ​​is balanced! 

          - NOTE: Chemical equations can have larger numbers in them than the ones in this example, but they aren’t more difficult. Just use your algebraic skills and you can solve all of them! You can apply knowledge of solving basic chemical equations to solving any chemical equation.