Physical Science- Dr. Clendening Exam 4

Oxidation

Oxidation

Loss of electrons and increase in oxidation number

Reduction

A gain of electrons and a decrease in oxidation number

Oxidizing Agent

the species that is reduced and is therefore gaining electrons

Reducing Agent

the species that is oxidized (Oxidation number increases) and it loses electrons

What are the principles of electrochemical cells?

the transfer of electrons generated from a redox reaction occurring in it results in the production of electric current

Nuclear reaction

• the process in which two nuclei, or a nucleus and a subatomic particle, collide to produce one or more new nuclei’s (Basically like having babies, think interracial marriage)

How are nuclear reactions balanced?

Based on the charge and mass number of the isotopes and radiation involved

Alpha Particles

1. Symbol: 4/2 He

2. Definition:

   1. consist of two protons and two nuetrons

   2. +2 charge

   3. Largest and slowest form of nuclear radiation

Beta Particles

1. Symbol 0/-1 β

2. Definition:

   1. Electrons

   2. -1 charge

   3. Weigh much less than quicker and move much quicker

   4. results from the conversion of a nuetron into a proton

Gamma particles

Symbol: 0/0 y

Definition:

1. Not particles at all but pure energy in the form of electromagnetic radiation

2. They have no charge and no mass

3. They have extremely high energy

What is the relative penetrating power of alpha particles?

Eliminated by your clothing and skin but extremely dangerous if ingested

What is the relative penetrating power of beta particles?

May be stopped by thin sheets of metal

What is the relative penetrating power of Gamma rays?

Shielded using thick layers of lead and concrete

Half-life

the time it takes for half of the present sample to decompose and is a constant for radioactive decays under present conditions

Radiometric dating

• If the rate of decay is constant, it should be possible to find the age of the sample

• The rate of decay or rate of change of the number of particles is proportional to the number present at any time

Terrestrial Planets

• The inner planets and are relatively small and dense

• Mercury, Venus, Earth, and Mars

Jovial Planets

• Jupiter, Saturn, Uranus, Neptune

• Outer planets

• Larger and mostly composed of gas (hydrogen and helium)

Nebula

A nebula is a large collection of particles (gas and dust) in the void of space

• Due to the gravitational attraction of the individual particles for each other these will tend to conglomerate into a larger mass

What is the nature of a reduction oxidation reaction?

• A reaction that involves the transfer of electrons between chemical species

Oxidation # F

-1

Ox # H

+1

Reflection nebulae

reflect light

Emission nebuale

emit their own light

Dark Nebulae

Opaque

The solar core

• The hottest and densest part of the sun, under which conditions H undergoes fusion to He.

• The source of the sun’s energy

The radiation zone

• transmits energy in the form of light

The convection zone

• a region of rising and sinking plasma as the plasma is heated from below and cooled from above

The Photosphere

• the coolest region of the sun and produces a great deal of light

The chromosphere

• Largely transparent with a pink color due to the emission of hydrogen atoms sometimes visble.

The corona

• flows out from the surface of the sun

• Very hot but not very dense

Habitable zone

• Water exists primarily as a liquid

The atmosphere

• regulates global temperatures

The magnetosphere

• Generated by the Earth’s core, protecting the planet from particles from the sun (solar wind)

Apogee

• The point in its orbit of the Earth in which the moon is the farthest away

Perigee

• The point in its orbit of the Earth in which the moon is the closest

Solar eclipses

• Results from the moon blocking part or all of the sun, casting the Moon’s shadow on the Earth

Umbra

The dark portion in a solar eclipse where totality may occur

Preumbra

• The lighter portion in a solar eclipse

Annular eclipse

• Occurs when the moon is at a far point in its orbit

• The umbra doesn’t reach the surface of the Earth.

Lunar eclipse

• Occurs when the Earth’s shadow covers the otherwise full moon

• The moon may appear red due to the light refracted by Earth’s atmosphere

The Asteroid Belt

• Orbits the Sun between Mars and Jupiter.

• The largest occupant of this region is the dwarf planet Ceres.

Meteoroids

• A small rock in interplanetary space

Meteors

• Meteroids when they burn through Earth’s atmosphere

Meteorites

• Meteor fragments which reach Earth’s surface

Kuiper Belt

• Lies beyond Neptune

• Houses Pluto as well as the remaining dwarf planets so far discovered

• Some comets originate from here as well

Comet

• Composed of rock and ice

• It must be small enough to be pulled out of the Kuiper Belt via gravity

• The tail originates from the volatile materials disturbed by the added heat and solar wind

Halley’s Comet

Comes around every 76 years and is mentioned in historical texts repeatedly

Distribution of mass in our solar system

• The sun is the largest object in our solar system and accounts for >99% of the mass in the solar system

• The distance between the planets and sun is massive and thus is conveniently expressed in astronomical units.

• A single astronomical unit is roughly 150 million km (1.5 × 10^8 km) which corresponds to the average distance between the Earth and the Sun

The Nebular Theory

1. Matter is gathered in a nebulae (which must have rotated)

2. Sufficient gravity pulls this material together (a collapse).

   1. Since the force of gravity increased as the nebula shrank, it would pull the particles into a sphere.

3. Conservation of momentum caused the mass to rotate faster as it shrank

4. Rotation flattened the solar system into a disk, from which the central portion formed the sun, and the planets formed from portions of the rings.

Dwarf Planets

• Ceres, Pluto, Haumea, Makemake, and Eris

• Locations:

  • Ceres- Located in the main asteroid belt between Mars and Jupiter

  • Pluto, Haumea, Makemake, and Eris are all located in the Kuiper Belt

Order of the Planets and labels terrestrial or jovial

1. Mercury -T

2. Venus-T

3. Earth-T

4. Mars -T

5. Jupiter-J

6. Saturn-J

7. Uranus -J

8. Neptune-J

Oort Cloud

• Similar to the Kuiper Belt except much further out

• Objects in this are small, and appear to have been “tossed out” from the main solar system

• Materials extend in all directions around the solar system

• Some comets originate from here

Constellations

• A collection of stars (a man made grouping)

• Are useful for tracking the positions of stars which have served as markers for seasons and global position for centuries

• 3 Forms of motion

  • Daily (Diurnal): due to the rotation of the Earth

  • Yearly (Revolutionary): due to the Earth’s orbit

  • Intrinsic: apparent motion relative to our position

Brightness of a star

• Varies due to their age, size, and distance

• Decreases with distance

Luminosity

• The total light energy of a star

• Increases with distance

Color of stars

• The energy and therefore color of light emitted by a hot object is proportional to temperature

• Blue stars are the hottest followed by yellow, then red

The HR Diagram

• Groups stars based on temperature and luminosity

Main sequence stars

• Less heat should mean lower luminosity for stars of the same size

Ox # O

-2

Cl Br and I Ox #

1

Main Sequence Stars (HR Diagram)

• Where most stars fall on the HR Diagram

• More massive stars are bigger, hotter, more luminous, and die faster

Giants (HR Diagram)

• Located towards the top right of the HR diagram

• Cool stars which are a little smaller and dimmer than supergiants

White Dwarfs (HR Diagram)

• Located in the lower left of the HR diagram

• Very hot stars

• Small

• Relatively dim

Supergiants (HR Diagram)

• Located in the upper right hand corner of the H-R Diagram, AKA the red-giant region

• Large with cooler temperatures

Planetary Nebula

• Gas and plasma expanding from the dying remnants of the core of a star

Nova

• The explosion resulting from binary stars

• Repeating events

Supernova

• Final collapse of a star as electrons and protons combine to form nuetrons

A Galaxy

• A large collection of stars (and other stuff)

What is our galaxy called and what is it an example of?

• The Milky Way

• A Spiral Galaxy

Elliptical (Type of galaxy)

• Tends to contain older stars

Irregular (Type of galaxy)

• May result from the collision (or near miss of two galaxies)

Clusters

• Collections of galaxies bound together by gravity

What is the name of “our” cluster?

• The Local Group

Superclusters

• A large group of smaller galaxy clusters or groups

What is the name of “our” supercluster?

• The Local Supercluster

What is happening to our cluster?

• Its slowly collapsing due to the pull of gravity

Does the universe have a center and are we at it?

• No. the universe has no discernible center

A Light Year

• The distance traveled by light in the vacuum of space in one year

• The speed of light is 2.998 × 10^8 m/s

How does the “red shift” of light relate to the movement of bodies away from each other?

• As bodies move away from each other, the wavelength of light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum.

How does light shift when objects are moving closer together?

• As objects move toward each other, the wavelength of light is compressed, so the light is seen as ‘shifted’ towards the blue part of the spectrum.

  • Blue shift

Hubble’s Law

• Definition: States that the redshifts in the spectra of distant galaxies (and hence their speeds of recession) are proportional to their distance.

• v= H * d

  • H= about 70 km/s/Mpc

The Big Bang

• A proposal that the universe started from a single point and “exploded” outwards

What are the limitations of Hubble’s law?

• Only Works for distant galaxies

What are the elements of supporting evidence for the Big Bang?

• The expansion of the universe

• Cosmological background radiation

• The Universe is mostly hydrogen and helium

Special relativity

• Deduced by Einstein

• Essentially that the laws of nature are the same assuming a constant frame of reference

How does special relativity relate to time?

• The rate at which time passes depends on your frame of reference

General relativity

• says that the observed gravitational effect between masses results from their warping of spacetime.

How does general relativity relate to time?

• The theory of general relativity predicts a time dilation in a gravitational field, so that, relative to someone outside of the field, clocks or atomic processes go slowly.