Spring Semester Review

Starting with a nebula, what is the life cycle of a low mass star?

Nebula, nuclear fusion, low-mass main sequence, red giant, planetary nebula, white dwarf.

Starting with a nebula, what is the life cycle of a high mass star?

Nebula, nuclear fusion, high-mass main sequence, supergiant, supernova, black hole or neutron star

What is nuclear fusion?

When a star's temperature is hot enough, hydrogen begins to fuse into helium and then denser elements.

Before the Big Bang, what were the characteristics of the universe?

A hotter, denser mass

What are some advantages of space telescopes such as the Hubble Space Telescope?

Study distant stars and galaxies, understanding stars and how they form

What did Christian Doppler’s study of waves eventually lead to us understanding about the Doppler shift?

The speed at which galaxies are moving away or toward each other.

What do light years measure?

 Distances in space by calculating the speed at which light travels.

What are trends that we can see on an HR diagram?

• Colors change according to color and often brightness

• Increases in temperature often increase in brightness

• Hotter stars are on the left

• Cooler stars on the right

• Cooler stars are also less massive

How can you describe the speed of galaxies the farther they are away from us?

The farther they are, the faster they are moving

What are typical temperature ranges of white dwarf stars?

15,000-25,000 K

How do white dwarfs compare in brightness to the sun?

They are dimmer, but hotter than the sun.

What types of stars are hotter and brighter than the sun?

White and blue main sequence stars, some supergiants

What is the luminosity of the sun?

The sun has a luminosity of one

How would you describe the sun as compared to other stars?

The sun is an average, yellow star

Where is the sun located in our galaxy?

Located on a spiral arm

What are nebulas and how do they form?

A cloud of gas and dust.  Planetary nebulae can form from dying stars.  Stars are born in a nebula.

What are the 3 types of galaxies?

Spiral, irregular, elliptical

Describe spiral galaxies.

Spiral arms extending from a central bulge, more gas and dust in the arms, stars forming in the arms

Describe irregular galaxies.

Younger stars as there is more dust and gas in these galaxies, do not have a defined shape, may be formed from collisions with other galaxies

Describe elliptical galaxies.

Mostly older stars, not much dust and gas, often look like a sphere or oval in space.

What does the movement of galaxies tell us about the size of the universe?

The universe is expanding and continually growing

What are the pieces of evidence for the Big Bang Theory?

Red shift (expansion of the universe), CMBR (Cosmic Microwave Background Radiation)

What is Cosmic Microwave Background Radiation?

It is all the leftover radiation from the Big Bang.  This radiation is detected in the microwave frequency of the EM Spectrum.  This low frequency radiation is found all over the universe.

qualitative data

descriptive and uses the senses to collect data. 

Adhesion

A property of water that allows it to adhere, or stick to another surface

Cohesion

The tendency of water molecules to stick to each other

Surface Tension

A property of water that due to the strong attraction between water molecules makes it difficult to break those molecules apart

Why are small insects such as water striders able to walk on the surface of water?

The force of the water strider on the surface of water is not able to overcome the surface tension of the water.

1. How does the surface tension of water impact plants and the movement of water in those plants?

Water has a high adhesive property.  This allows the water to stick to the walls of the xylem to move the water throughout the plant.

In a Bohr model, where do we find valence electrons?

The outer energy level

What do valence electrons determine for groups of atoms?

Valence electrons determine the reactivity of atoms and help us understand the chemical properties of those atoms.

If we want to determine the density of a regularly shaped object, what tools would we need?

Ruler, scale, calculator

If we want to determine the density of an irregularly shaped object, how would we do that and what tools would we use?

We would use water displacement to determine the volume of the object.  The tools needed would be  a graduated cylinder, scale, and calculator.

What determines the mass of an atom?

The total number of protons and neutrons in the nucleus of the atom.

hat are the 3 subatomic particles?

Protons, neutrons and electrons

What are the charges and locations of subatomic particles?

Protons- positive and in the nucleus

Neutrons- no charge (neutral) and in the nucleus

Electrons- negative and outside the nucleus in the electron cloud

Describe what is happening in a chemical reaction?

In a chemical reaction the bonds of the reactants break apart, atoms rearrange, and new bonds are formed.  These new bonds are new substances that have new chemical and physical properties.

What is a coefficient?

A coefficient is a large number in front of a chemical formula that tells you the number of molecules of that substance.

How do you apply a coefficient when counting the number of atoms in a compound?

The coefficient is multiplied by the number of each atom in the molecule.  It is similar to the distributive property in math.

what is the law conservation of mass?

The law of conservation of mass states that matter is neither created nor destroyed in a chemical reaction.  This means that there will be the same amount of atoms on each side of a chemical equation, as well as the same elements.

1. In a chemical reaction that begins with 25.4 g of hydrogen and 13.2 g of oxygen, what should the mass of the product be

25.4 + 13.2 =38.6g

What are the properties of acids?

Sharp or sour flavor

Electrolyte conducts electricity

Low pH

Reacts with litmus paper to change it colors

Corrosive

What are the properties of bases?

Electrolyte that conducts electricity

Feels slippery when mixed with water

High pH number

Reacts with litmus paper to cause color changes

1. How does gravity affect adhesion with a moving object such as a car?

Smaller water droplets will stick to the windshield of a car because the mass is small.  Larger droplets will feel the effect of gravity more and will be pulled from the windshield.

What is the pH for an alkaline solution such as water?

7

1.  In the formula C₆H₁₂O₆ + 6O₂ → 6H₂O + energy, how many atoms of each element are present in the equation?  What is the total number of atoms?

Carbon- 12

Hydrogen- 24

Oxygen- 32

Total- 68

Why are halogens and alkali metals so reactive, and often extremely reactive together?

Halogens only need to gain one electron to complete their outermost energy level, while alkali metals need to lose one.  This makes them easily reactive with each other to form salts.

Discuss how we determine valence electrons in elements using a periodic table.

Group numbers help us to know the valence electrons in elements in groups 1-2 and 13-18.  Transition metals do not follow the same rules, as they have 2 or 3 valence electrons.  Groups 1 and 2 the group number is the number of valence electrons.  In groups 13-18, the group number minus 10 is the number of valence electrons.

What is the difference between mass number and atomic mass?

Mass number is always a whole number and is a count of the number protons plus neutrons.  Atomic mass is the number on the periodic table under the chemical symbol.  This number is typically a decimal number because it is the average mass of all known isotopes of an element.

What does the period tell us on the periodic table?

Period tells us the number of energy levels that an element has.  Elements in period 4 will have 4 rings, or energy levels, of electrons surrounding the nucleus.

Elements

pure substances that can not be broken down into simpler substances, found on the periodic table

Compounds

pure substances that are combined elements from the periodic table; cannot be broken down by physical means

Heterogeneous mixtures

two or more substances that can be distinguished from each other and physically separated

Homogeneous mixtures

 typically when a substance is dissolved in water; salt water, sugar water, Kool-aid, etc.  These are not easily distinguishable

What is a wavelength?

The distance between two corresponding points on a wave, such as from crest to crest or trough to trough.

What is frequency?

The number of wave cycles that pass a point in one second, measured in hertz (Hz).

Explain how wavelength and frequency are related

As frequency increases, wavelength decreases,

As frequency decreases, wavelength increases.

Arrange the parts of the electromagnetic spectrum from the lowest to the highest frequency.

Radio Waves, Microwave, Infrared Waves, Visible Light Waves, Ultraviolet, X-Ray, and Gamma Rays

Which part of the electromagnetic spectrum has the highest frequency in hertz (Hz), and what does that mean about its energy and wavelength?

They have the highest frequency, shortest wavelength, and most energy. 

They can penetrate materials and are used in cancer treatment and by astronomers studying high-energy cosmic events.

1. Which part of the electromagnetic spectrum has the lowest frequency in hertz (Hz)

Radio waves are the lowest-frequency, longest-wavelength, and least amount of energy.

What is the deal with the energy and wavelength of radio waves?

They're great for communication (like radio, TV, and cell phones) because they can travel long distances and penetrate through the atmosphere.

Where do radio waves fall on the electromagnetic spectrum in terms of frequency (Hz)

Radio Waves Have the longest wavelengths, the lowest frequencies, and the lowest energies. They produce a Hz of 10^4.

Examples of Radio Waves

AM/FM radio, TV, remote controls, garage door openers, alarm systems, baby monitors

Where do microwaves fall on the electromagnetic spectrum in terms of frequency (Hz)

They second on the EM spectrum with Shorter wavelengths than radio waves, with higher frequencies and energy. They produce a Hz of 10^8.

Examples of Microwaves

microwave ovens, cell phones, RADAR, satellite communications

Where do Infrared waves fall on the electromagnetic spectrum in terms of frequency (Hz)

They are right before visible light and can not be seen, but they can be felt when a warm object radiates heat.. They produce a Hz of 10^12.

What are some everyday uses for Infrared Lights?

remote controls, thermographs, heat-sensing animals

Where do visible waves fall on the electromagnetic spectrum in terms of frequency (Hz)

Visible light is the part of the EM spectrum that human eyes can detect.  They produce a Hz of 10¹⁵.

what are some everyday uses for visible light

All visible light

Where do ultraviolet waves fall on the electromagnetic spectrum in terms of frequency (Hz)

Ultraviolet rays occur naturally in sunlight.  They produce a Hz of 10¹⁶. 

examples of UV rays

sterilizing water  and medical equipment can impact individual cells

Where do X-rays waves fall on the electromagnetic spectrum in terms of frequency (Hz)

 X-rays have very high frequencies and energy. They produce a Hz of 10¹⁸

 what are some everyday uses for UV rays

 x-ray images

Where do Gamma waves fall on the electromagnetic spectrum in terms of frequency (Hz)

They have the highest wavelengths and carry the most energy.  They produce a Hz of 10²⁰.

Examples of Gamma Rays

fighting tumors

1. What part of the electromagnetic spectrum can you see

Visible light is the only wave you can see. 

How is frequency and energy related?

Frequency and energy are directly proportional, meaning a higher-frequency wave carries more energy

wavelength

The distance between two consecutive peaks (or troughs) of a wave

As you move from radio waves to gamma rays across the EM spectrum what happens

Wavelengths get shorter, Frequencies get higher, Energy Increases

What is the relationship between wavelength and frequency when waves travel at a constant speed?

When waves travel at a constant speed, the relationship between wavelength (λ) and frequency (f) is inversely proportional.

What does increasing frequency mean?

Shorter Wavelength

What does decreasing frequency mean

Longer wavelength

What is a medium

 the substance or material through which a wave travels. Material can be a solid, Liquid, or a Gas.

What does a medium have to do with mechanical waves

they need a medium to travel

What does a medium have to do with electromagnetic waves

Electromagnetic waves do not need a medium

inertia

the tendency of an object to resist a change in its state of motion

Newton’s 1sr law

Newton’s 1st law states that an object at rest will remain at rest unless acted on by an unbalanced force.  An object in motion will remain in motion unless acted on by an unbalanced force.

newton’s 2nd law

application of force, mass, and acceleration.  Force is equal to the mass times the acceleration.

newton’s 3rd law

for every action there is an equal and opposite reaction.

why will a soccer player kick a soccer ball, but not a bowling ball?

Soccer balls have much less mass than bowling balls.  If a player kicked a bowling ball with the same force that they kicked a soccer ball, they would greatly hurt their foot, or even break it.  That much mass would be extremely painful on the foot.

How does friction affect movement

It resists movement and is considered an opposing force

How does friction apply to Newton’s 1st law of motion?

It helps to slow or stop an object that is moving.  This is an unbalanced force that causes a change in motion.

What is force?

a push or a pull that causes motion

What is an independent variable?

It is the variable in an experiment that we are testing, or intentionally changing.

What is a dependent variable?

The response to what we changed.  It is the measured variable.

how do you calculate force?

Force = Mass x Acceleration

How do you calculate mass

Mass = Force/Acceleration

How do you calculate acceleration

Acceleration = Force/Mass

If Jeremy used 20 N of force, and Sofia 14 N, what was their total force to move the box?

34N

If a box was 100kg, and the Net Force was 34N, whats the accleration?

.34 m/s/s