Suppose 20 g of liquid hydrogen peroxide is heated so it completely breaks down into liquid water and oxygen gas. Which best describes the total mass of the water and oxygen that was produced? a. more than 20 g because of the addition of heat b. more than 20 g because there are now two substances less than 20 g because oxygen gas is very light d. 20 g because no matter is added or removed
A container is filled with 100 mL of water and placed in a freezer. The water in the container freezes at 0C. A second container filled with 90 mL of water is placed in a second freezer. At what temperature does this second container of water freeze? a. 10C b. 1C c. 0C d. 10C
Because sulfur cannot be decomposed by simple chemical methods into two or more different substances, it is classified as a. an element. b. a compound c. a mixture. d. a molecule
Which of the following is a characteristic of elements? a. They break down when reacting with acids b. They can be altered with an electric current. c. They are always metals. d. They cannot be divided into smaller substances.
The periodic table of the elements is systematically organized according to the rate at which the elements chemically react b. hardness of the elements. c. structure of the atoms of the elements. d. radioactivity of the atoms of the elements.
Formation & Composition of Minerals • Minerals are naturally occurring elements or compounds • Most result from the chemical combination of two or more elements • Ex.- oxygen & silicon combine to form quartz • Native elements- mineral made of only one type of elements • Found uncombined in nature • Ex.- gold, silver, copper, & sulfur • Many minerals form from Magma • Mineral crystals form when magma cools • How and where the magma cools determines the size of the crystals • Mineral crystals may also form from compounds dissolved in a liquid such as water c o p p e r
Identifying Minerals • Minerals have certain physical properties that can be used to identify them • Some properties can be observed just by looking at the mineral • Color • Luster • Crystal shape • How it breaks • Certain properties can only be determined by testing • Hardness • Streak • Specific Gravity • Acid test
From Minerals to Rocks • “Minerals are to rocks as letters are to words” (Quote from Professor R. Lingner, WSC) • Rocks- Hard substances composed of one or more minerals • Usually made of more than one type of mineral • May contain naturally occurring substances that would not be considered a mineral • Are grouped according to how they form as either igneous, sedimentary, or metamorphic
The Rock Cycle • Rock Cycle- Diagram used to illustrate how and why the three types of rocks are related to each other • Summarizes the processes responsible for the formation and breakdown of igneous, sedimentary, and metamorphic rocks • Rocks go through changes due to cooling, weathering, compaction, heat & pressure, and melting
Rocks found on Earth are classified as sedimentary, metamorphic, or igneous based on a. where the rocks were found. b. how the rocks were formed. c. the composition of the rocks. d. the color and shape of the rocks.
When igneous rock is changed into metamorphic rock, which form of energy is this process? a. heat b. chemical c. magnetic d. light
Typically, sedimentary rocks are formed a. only in erupting volcanoes. only under great pressure and high temperatures. below Earths surface as magma cools and crystallizes. d. from materials that settle.
Composition of the Atmosphere The atmosphere is a mixture of gases, liquids, and suspended solids that surrounds our planet • Gases-include nitrogen, oxygen, carbon dioxide, water vapor and trace gases • Mostly nitrogen (78%) and oxygen (21%) • Water vapor- enters the air by evaporation from the ocean & other water sources • Clouds, fog, and dew are caused by water vapor in the air • Suspended solids- include dust, sea-salt, smoke, pollen, bacteria, and chemicals from industry & transportation
Structure of the Atmosphere The atmosphere is divided into layers based on changes in temperature • Troposphere- Begins at sea level and extends approximately 8 to 18 kilometers depending on location and season • Stratosphere- Extends from the tropopause to an altitude of about 50 Km • Mesosphere- Extends from the stratopauseto about 80 Km above the Earth’s surface • Thermosphere- Begins after the mesopause, but has no definite upper limit
Harmful ultraviolet rays from the Sun are primarily absorbed by a. dust b. ozone c. land masses d. water vapor
Large amounts of industrial gases are released into the atmosphere every day. What happens to those gases? a. They are broken down by ultraviolet light from the Sun. b. They are converted into nitrogen and oxygen. c. They rise through the atmosphere and go into outer space. d. They remain in the atmosphere for long periods of time.
Heating the Atmosphere • Almost all of the energy heating our atmosphere comes from the sun (called radiant energy) • Not all of the sun’s radiant energy reaches Earth’s surface; some is reflected back into space, scattered, or absorbed by gases and clouds in the atmosphere • Solar energy which reaches the Earth’s surface heats the atmosphere in one of three ways: radiation, conduction, or convection
Heating the Atmosphere • Radiation- The transfer of energy by electromagnetic waves such as light • Conduction- The direct transfer of heat energy from one substance to another • Earth’s surface is warmed by radiant energy • Air coming in contact with Earth’s warm surface is heated by conduction • Convection-The transfer of heat energy in a fluid ( gas or liquid) • Causes warmer fluids to rise in colder ones • Convection currents in the atmosphere are caused by the unequal heating of the Earth by the sun • Most of the heat energy in the atmosphere is transferred by convection currents
Global Temperature Variations • The temperature of the air can be affected by many factors • Amount of sunlight • Wind • Latitude • Altitude • Proximity to oceans and other water bodies
Why do areas in the middle of a large continent generally have more extreme differences in temperature than areas near the coastline? There are generally more clouds near the oceans. Landlocked areas are usually at a lower altitude than coastline areas. Coastlines are usually surrounded by mountains that block air masses. Oceans change temperature slowly and regulate the temperature of nearby land.
Seasons on Earth • The different seasons are caused by the Earth being tilted 23 ½ degrees on its axis • The tilt of the Earth on its axis, in conjunction with it’s rotational path around the sun, causes an unequal distribution of light and heat at the surface
Which of the following is most important in producing the seasons on Earth? Earths gravitational attraction to the Sun b. the Moon’s revolution around Earth c. the distance of Earth from the Sun the tilt of Earths axis as it revolves around the Sun
Atmospheric Pressure • Air pressure- Measure of the force of the atmosphere pressing down on Earth’s surface • The pressure at any point on the Earth is equal to the weight of the air directly above that point • Air pressure depends on the density of the air - the denser the air, the higher the pressure • Differences in air pressure cause winds and changes in the weather
Winds • Winds result from the unequal heating of the atmosphere by the sun • This causes pressure differences • Winds occur when air moves from areas of high pressure to areas of low
Types of Winds There are two types of winds- local & global • Local winds- Movement of air caused by differences in the heating and cooling rates of land and water • Global Winds- Large scale movement of air caused by the unequal heating of the earth’s surface • Convection currents in the atmosphere cause cold, dense air from areas near the poles to sink and move along the surface, forcing warm air near the equator aloft • Create a worldwide system of wind and ocean currents
Local Winds • Sea breeze- Winds occurring during the day when cool, dense air from over the water flows inward and forces the warm air over the land to rise • Land breeze- Winds occurring at night when cool air from over the land flows seaward and forces the warm air over the ocean to rise
Global Winds • Major wind patterns produced by the unequal heating of Earth’s surface in combination with its rotation • Winds blow from areas of high pressure to those of low pressure • Types of global winds: • Trade Winds-Blow toward the equatorial low (0° latitude) from the subtropical highs (30° lat.) • Prevailing Westerlies- Blow from the subtropical highs (30° lat.) to the sub-polar lows (60° lat.) • Polar Easterlies- Cold, dense air mass which moves from the polar highs (90° lat.) to the sub-polar lows (60° lat.)
The Origin of the Universe • Astronomers believe that billions of years ago all the matter and energy in the Universe was concentrated into single hot dense point called a singularity • Tremendous amounts of heat and pressure made this point so unstable that it exploded • According to the Big Bang Theory , the Universe began to expand after an enormous explosion of concentrated matter and energy • As it expanded, the Universe cooled • Atoms formed after a few hundred million years • The first stars and galaxies formed after about 200 million years
Galaxies • A galaxy is a large system of stars and other cosmic bodies • Galaxies are the major features of the Universe • There may be more than 100 billion major galaxies • There are three main types of galaxies
The Solar System • A huge rotating system consisting of the Sun, eight planets and their satellites, dwarf planets, asteroids, comets, and meteors • Astronomers use the Nebular Theory to explain the formation of our solar system
Inner vs. Outer Planets • The asteroid belt is used as a dividing line to separate the planets into two groups • The inner planets- Mercury, Venus, Earth and Mars (located between the Sun & the asteroid belt) • The outer planets- Jupiter, Saturn, Uranus, and Neptune (located beyond the asteroid belt)
Terrestrial vs. Jovian Planets • Terrestrial Planets- Planets that are Earth-like, in that they have a solid, rocky surface • Mercury, Venus, Earth, and Mars • Jovian Planets-Planets that are Jupiter-like, in that they have thick gaseous atmospheres that surround layers of liquid hydrogen and helium, and small rock and iron cores • Jupiter, Saturn, Uranus, and Neptune
Rotation vs. Revolution • Rotation- The time it takes an object to spin once on it’s axis (a day on the planet) • Revolution- The time it takes to orbit another body in space ( a year on a planet)
The Moon’s Phases • The relative motions of the Earth, Moon and Sun cause a change in the moon’s appearance • The daily changes in the Moon’s appearance are called phases • Waxing Phases When the moon appears to grow larger as it goes from being a new moon to a full moon • Waning Phases When the moon appears to grow smaller as it goes from the full moon phase to the new moon
Eclipses • Occur when one object in the sky is blocked from view by another • Named for the object that we don’t see • During an eclipse, the shadow of one object falls on the other • The shadow has two parts, a dark inner shadow (umbra) and a lighter outer shadow (penumbra) • Being in the umbra produces a total eclipse, while being in the penumbra, a partial eclipse
Solar Eclipses Blocking of the Sun that occurs when the new moon comes directly between the Sun and the Earth
Lunar Eclipse Blocking of the moon that takes place when Earth comes directly between the Sun and the full moon
Which of the following is a necessary condition for a lunar eclipse to occur? a. The Moon must be full. b. The Moon must be waxing c. It must be the beginning of the month. d. It must be winter in the Northern Hemisphere.
How Light Behaves • Light travels in straight-line paths called rays • Reflection- When light strikes a surface, some of it bounces back • Refraction- The bending of light due to a change in speed
Lenses Refract Light • Convex lenses-Lenses that are thicker in the center than at the edges • Bend rays of light toward the thicker center of the lens • The amount of refraction depends on how much the lens curves (the greater the curve, the more the light is refracted) • Converge light rays at the focal point • Concave Lenses-Lenses that are thinner in the center than at the edges • Bend rays of light outward toward the thicker ends of the lens • Diverge rays of light
Evidence for Plate Tectonics • Continental Drift • Location of volcanoes, earthquake belts and mountains • Sea-floor Spreading • Paleomagnetism
Evidence for Continental Drift • Shape of the continents • Similar fossil deposits on continents thought to have been joined • Rock formations that end at the edges of continents • Glacial deposits (evidence of past climates) • Distinctive rock types
The primary cause of continental drift, earthquakes, and volcanic eruptions is a. convection currents beneath Earths crust b. the rotation of Earth on its axis. c. the gradual sinking of Earths crust. d. heat from the Sun warming Earth.
Plate Boundaries There are three basic types of plate boundaries • Divergent- moving apart • Convergent- moving together • Transform fault- sliding past each other
The Earth’s Iinterior • The four layers of the Earth are the crust, mantle, inner core and outer core • These layers vary greatly in size, composition, temperature, and pressure
Which is the thickest layer of Earth? a. crust b. inner core c. mantle d. outer core
Gravity Gravity is the force of attraction between objects The strength of the gravitational force between objects depends on: - The distance between the objects ( the gravitational force between objects decreases with distance) -Mass ( the greater the mass of an object, the greater it’s gravitational force)