Earth Science: Chapter 3: The Sun- Fusion, Matter, and Energy Production: Fall 2017

LT 3.1: I CAN describe the structure of atoms, including its subatomic particles.

Matter is anything that has mass and volume (takes up space)
Atoms are the smallest part of an element that retain the properties of that element.  Atoms are made up of subatomic particles called: Electrons, Protons, and Neutrons
Element: a piece of matter that cannot be broken down into a simpler substance. There over 100 elements in the universe.  92 of those are naturally occurring in the earth.

Subatomic particles organizer

Electrons (e-)	Protons (p+)	Neutrons (n0)	
Purpose:  Determine chemical and physical properties	Purpose:  Determine what element it is.  (Atomic # is # of protons.)	Purpose:  Contribute mass and if there is an unequal ratio of protons to neutrons in the nucleus it causes the atom to be unstable (also called radioactive)	
Charge:   Negative	Charge:  Positive	Charge:  Neutral (No charge)	
-1	          +1	            0	
Mass:  “No Mass”  (even though it is matter but it takes almost 1837 electrons to equal the mass of 1 proton)	Mass:   1 amu
(atomic mass unit)	Mass:    1 amu	
Location:  Traveling around the nucleus in energy levels at ALMOST the speed of light.	Location:  In the nucleus	Location:  In the nucleus	
In a neutral atom # of electrons = # of protons	Atomic # is the # of protons	Mass # - Atomic # = # of neutrons	

•	The nucleus of an atom is only a region or area in which the protons and neutrons are found.  
•	It is NOT the brain of the atom.  
•	Atoms are not happy or sad but will react with other substances to become stable. 
•	The nucleus of an atom is held together by what is called the strong force or strong nuclear force.  This force is strongest known force in the universe.  It has to be so strong due to the fact that the positive protons repel each other and would have a tendency to fly apart.  Remember that the neutrons are neutral and neither attract or repel.  The only reason the atom is stable is due to the strong force holding the nucleus intact.  

LT 3.2 I CAN explain the process of fusion in the Sun.
Driving question: What fuels our sun and will it ever run out of energy?

https://youtu.be/Ux33-5k8cjg How does the Sun make energy?  Veritasium

Nuclear Reactions	
Ex:  Fusion in the stars	
Nuclei (more than 1) are being combined	
Deal with strong force 	
Einstein’s theory of relativity proved that mass can be converted to energy (E=mc2)	
Can release tremendous energy because mass is converted to energy	

There are 2 types of nuclear reactions – fission which is taking place right now in Earth’s crust where elements such as uranium are breaking down into other elements and releasing energy in the process.  The other type is fusion where, in stars 2 hydrogen nuclei fuse together to make a helium nucleus.  The way to remember fusion is to remember that it has a U in its spelling and fusion is what takes place in our SUN.  

Einstein’s theory of relativity:  E = mc2 proved that mass could be converted to energy and that energy could be converted to mass.  In fusion, part of the mass of the 2 hydrogen nuclei combining is converted to energy. When you think of the trillions of nuclear reactions taking place in the sun right now, it is easy to see why it can shine so brightly and affect every part of our solar system.  

Fusion FACTS:
•	DEF – the combining of 2 or more light nuclei to form a nucleus of slightly less  _____________ and tremendous amounts of ______________
•	Fusion can only take place under conditions of high temperature and pressure such as is found in the ____________________.
•	Fusion reactions fuel the Sun which in turn fuels Earth and all life on our Earth.  Fusion produces every type of electromagnetic radiation 
•	The source of the Sun’s energy is nuclear fusion.  Deep in the solar interior, at a temperature of _________________________ K, a nuclear reaction called the proton-proton chain converts four ____________________nuclei (protons) into the nucleus of a ___________________ atom.  During the reaction some of the matter is converted to the energy of the Sun.  A star the size of the Sun can exist in its present state for ___________________________ years.  

Note:  Hydrogen nuclei are sometimes just called protons as was stated above.  Why do you think this is so?

LT 3.3:  I CAN DESCRIBE AND EXPLAIN THE LAYERS OF THE SUN

The Sun is the largest object in the solar system, in both size and mass.  It would take 109 Earths lined up edge to edge to fit across the Sun, or almost 10 Jupiter’s.  

The density of the Sun at its center is 13X the density of lead.  To give you some idea, the density of the Sun using a pair of dice would mean that the dice would have to weigh about 2 pounds.  Density is mass per unit of volume or mass divided by volume.    

The Sun is made up of primarily 6 layers:
	Core
	Radiation Zone
	Chromosphere
	Convection Zone
	Photosphere
	Corona

Structure of the Sun
The Core: the center of the star. The core is about 20% of the star’s radius. Nuclear fusion occurs in the core.  This is the energy production layer of the sun.  It is extremely dense (high pressure) and hot in the core.  Our Sun’s core can reach 15 million Kelvin. Larger stars (more mass) can reach even higher temperatures.

Radiative Zone
Above the core is a region called the radiative or radiation zone.  In this zone, energy is transferred from particle to particle by radiation, as atoms continually absorb energy and then re-emit it.

Convection Zone
Above the radiation zone is the convective or convection zone.  In this zone, moving volumes of gas carry the energy the rest of the way to the Sun’s surface through convection.  It take about 170,000 years to transfer energy to the surface of the Sun through this zone.

Photosphere
“Sphere of Light”
It radiates most of the sunlight we see and is considered the Sun’s surface but really is not a true surface like we understand with respect to Earth. It is a very thin layer compared to the rest.  It has numerous blemishes called granules which appear lighter and are surrounded by darker regions.  These granules, which usually are about the size of Texas, are brighter because of the hotter gases that are rising from below.  Each granule lasts around 20 minutes and new ones are constantly popping up giving the appearance of boiling.  

Chromosphere 
“Color Sphere”
Just above the photosphere is the chromosphere, which is relatively thin and made up of hot, incandescent (glowing) gases a few thousand kilometers think.  It is observable for a few moments during a total solar eclipse or by using a special instrument that blocks out the light from the photosphere.  Under such conditions, it appears as a think red rim around the Sun.  Made up primarily of hydrogen makes this sphere’s red color. 

Corona
The outermost portion of the solar atmosphere, which is only visible also when the photosphere is covered.  This envelope of ionized gases normally extends a million kilometers from the Sun and produces a glow about half as bright as the full Moon.  At the outer edges of the corona, the ionized gases have speeds great enough to escape the gravitational pull of the Sun.  The streams of protons and electrons that pull away from the corona constitute the solar wind.

LT 3.4: I CAN EXPLAIN THE ORIGIN OF SOLAR FLARES, SUNSPOTS AND SOLAR WINDS AND THEIR EFFECT ON EARTH.

https://youtu.be/2zOlkIyg3iE       What is Solar Wind and how they effect Earth?

Solar winds

•	Solar winds occur when streams of protons and electrons escape the corona.  
•	These protons and electrons travel outward through the solar system at very high speeds (250 to 800 kilometers per second) and eventually are lost to interstellar space (the space between stars)  
•	Solar winds interact with everything in our solar system, continually bombarding lunar rocks and altering their appearance.  
•	Although Earth’s magnetic field prevents the solar winds from reaching our surface, these winds do affect our atmosphere.  
•	When the ejected particles reach Earth and disturb the ionosphere, radio communication is disrupted and the auroras, also called the Northern and Southern Lights, occur.

https://youtu.be/ZC2dfDS8g0Q       Video is entitled:  What are Sunspots?  

Sunspots

•	A dark spot on the Sun’s photosphere, which is cool by comparison to the surrounding photosphere.  
•	Sunspots usually occur in pairs and last for a few months. 
•	The number of sunspots observable on the solar disk varies in an 11-year cycle.  
•	The most explosive events associated with sunspots are solar flares.  

Solar flares

•	A sudden and tremendous eruption in the solar chromosphere.  
•	Violent eruption of radiation and particles from the Sun’s surface that is associated with sunspots.  
•	Flares are brief outbursts that release enormous quantities of energy that appear as a sudden brightening of the region above sunspot clusters.  
•	During the event, radiation and fast-moving atomic particles are ejected, causing the solar wind to strengthen.
•	There is evidence that the solar activity cycle affects climates on Earth.  For example, some scientists have found evidence of subtle climate variations within 11-year periods.   
•	Also, there were severe weather changes on Earth during the latter half of the 1600s when the solar activity cycle stopped and there were no sunspots for nearly 60 years.  
•	No one knows why the Sun’s cycle stopped.  Those 60 years were known as the “Little Ice Age” because the weather was very cold in Europe and North American during those years.
•	The part of our Earth that protects us from solar flares is the magnetosphere.

LEARNING TARGET 5:  I CAN DESCRIBE AND EXPLAIN THE CHARACTERISTICS OF WAVES

https://youtu.be/cfXzwh3KadE   The Electromagnetic Spectrum

B.  Electromagnetic Radiation
	1.  In the wave model light is believed to consist of electromagnetic waves
                that travel in a vacuum at the speed of 3 x 1010 cm/s or 3 x 108 m/s.
	2.  Electromagnetic radiation includes:
		Longest wavelength 		radio waves           Lowest frequency
						microwaves          
						infrared light
						visible light	
						ultraviolet light
						x-rays                                    
		Shortest wavelength		gamma rays         Highest frequency
	     (Remember to show that this is going from the longest wavelength
                     to the shortest and the lowest frequency to the highest)
	3.  In order to understand waves one must know the parts of a wave:  draw and label amplitude, crest, wavelength and trough

_________________________________________________________________________

a.  amplitude – is the height of a wave from the origin to the crest.
		b.  wavelength –  (λ- lambda) is the distance between two crests.
		c.  frequency –- nu) is the number of wave cycles to pass a 
                                  given point per unit of time.  Frequency and wavelength are
                                  inversely proportional to each other.
			= c/wavelength
			frequency = speed of light/wavelength
		     This means that as the wavelength of light increases frequency
                                  decreases.
		d.  The SI unit for frequency is cycles per second which are called
                                   Hertz, Hz.
	4.  Sunlight consists of light with a continuous range of wavelength and frequencies. 
                    Sunlight passed through a prism is separated into a spectrum of colors.
a.	R O Y G B I V   (Red, orange, yellow, green, blue, indigo, violet)	
b.	Red has the longest wavelength and violet has the shortest
                                    wavelength and the highest  frequency.