Download Lesson 1 | Scientific Inquiry

Mid-Term Study Guide
Scientific Inquiry
A. Understanding Science. Define the terms.
1. Inference:
A logical explanation of an observation drawn from prior knowledge.
2. Independent variable:
The factor in an experiment that is manipulated or changed by the investigator.
3. Constants:
All of the factors in an experiment that do not change.
4. Observation:
Using one or more of your senses to gather information.
5. Dependent variable:
The factor in an experiment that changes as a result of changes to the independent variable.
6. Conclusion:
The outcome of an experiment. Where results are analyzed to determine if your hypothesis was supported or not supported.
7. Prediction:
A statement about what will happen next in a series of events.
B. Scientific Theory and Law
1. An explanation of observations or events based on knowledge gained from many observations and investigations is called a(n) theory.
2. A rule that describes a repeatable pattern in nature is called a(n) law.
3. A scientific law only states that a pattern will happen; it does not explain why or how the pattern happens.
Earth’s Motion
A. Earth and the Sun
1. Revolution is the movement of one object around another object.
a. The path a revolving object follows is its orbit,
b. It takes approximately one year for Earth to make one revolution around the Sun.
c. Earth moves around the Sun because of the pull of gravity between Earth and the Sun.
B. Seasons
1. Earth’s seasons change in a yearly cycle because of the tilt of its rotation axis and Earth’s revolution around the Sun.
a. The part of Earth tilted toward the Sun experiences seasons of spring and summer.
b. The part of Earth tilted away from the Sun experiences seasons of autumn and winter.
2. During a(n) solstice, Earth’s rotation axis is the most toward or away from the Sun.
3. During its revolution, Earth’s axis does not lean toward or away from the Sun during a(n) equinox.
Earth’s Moon
A. The Moon’s Formation
1. Scientists hypothesize that the moon formed from rock that was in a ring around Earth. This ring formed when Earth collided with an object
about the size of Mars.
2. Craters form when an object crashes into the surface of another object.
a. Light-colored streaks called rays extend in all directions from some craters.
3. Large, dark, flat areas on the Moon are called maria.
4. Highlands are light-colored areas on the Moon’s surface.
B. Phases of the Moon
1. More of the Moon’s near side is lit each night during the waxing phases.
2. Less of the Moon’s near side is lit each night during the waning phases.
3. At the end of the lunar cycle, you cannot see any of the lit side of the Moon, which is called the new moon phase.
4. Half of the moon is visible during the first and third quarter.
Eclipses and Tides
A. Shadows—the Umbra and the Penumbra
1. The darker central part of a shadow is called the umbra where light is totally blocked.
2. The lighter outside part of a shadow is called the penumbra where light is partially blocked.
B. Eclipses
1. During a(n) solar eclipse, the Moon’s shadow passes over Earth’s surface.
2. The Moon’s orbit is slightly tilted compared to Earth’s orbit so you don’t see an eclipse each month.
3. During a(n) lunar eclipse, Earth casts a shadow on the Moon.
C. Tides
1. The daily rise and fall of sea level is called a(n) tide.
2. The main cause of tides is the gravitational pull of the moon on Earth.
a. A(n) high tide occurs on the side of Earth that is closest to the Moon and on the opposite side of Earth.
3. During a(n) spring tide, Earth, the Sun, and the Moon are positioned in a straight line. At this time, high tides are higher than usual, and low
tides are lower.
4. During a(n) neap tide, Earth, the Sun, and the Moon form a right angle. At this time, high tides are lower than usual, and low tides are
higher.
The Structure of the Solar System
A. The Sun, planets and other objects in the solar system formed when gravity pulled together the material of a nebula.
B. The Inner Planets
1. The inner planets are those closest to the Sun.
2. The inner planets are made of rocky and metallic materials.
a. Because of its small mass, Mercury’s gravity is not strong enough to hold gases to its surface.
b. Venus is covered by a thick layer of clouds.
c. The high temperatures on Venus are caused by the greenhouse effect.
C. The Outer Planets (The Gas Giants)
1. The outer planets are made of materials that are usually gases on Earth.
2. Gravitational forces produced by the large sizes of these planets and cold temperatures change gases into liquids or solids.
3. The gas giants are made mostly of hydrogen and helium.
D. A dwarf planet has objects similar in size orbiting near it or crossing its orbital path.
E. Asteroids orbit the Sun in a band between mars and Jupiter.
F. Comets are made up of rocks, ice, and dust.
1. Many comets take more than 200 years to orbit the Sun. They come from the Kuiper Belt.
G. Meteoroids
1. A small, rocky particle that moves through space is a(n) meteoroid.
2. As it passes through Earth’s atmosphere, friction with the air makes a meteoroid and the air around it glows.
3. A streak of light in the atmosphere made by a glowing meteoroid is a(n) meteor.
The View from Earth
A. Measuring Distances
1. The apparent change in an object’s position that occurs when you look at the object from two different points is called parallax.
2. Within the solar system, astronomers measure distances using the Astronomical unit, which is defined as the average distance between
Earth and the Sun.
3. Outside the solar system, scientists measure distances in a unit called a(n) light year, which is the distance light travels in 1 year.
B.
Measuring Brightness
1. Scientists measure a star’s brightness in two ways: how bright the star seems to be when it is viewed from Earth and how bright the star
actually is.
a. The measure of how bright an object appears from Earth is called the apparent magnitude of the object.
b. The astronomer Hipparchus was the first to describe apparent magnitude.
2. Stars appear to be bright or dim depending on their distance Earth, but stars have an actual, or absolute magnitude.
a. The true brightness of an object is called its luminosity.
b. A star’s luminosity depends on the star’s temperature and size.
The Sun and Other Stars
A. How Stars Shine
1. When the nuclei of several atoms combine to form one larger nucleus, the process of nuclear fusion occurs.
2. A large ball of gas that is held together by gravity and that has a core so hot that nuclear fusion occurs is called a(n) star.
B. Composition and Structure of Stars
1. A typical star has three inner layers: the core, the radiative zone, and the convection zone.
2. The three outermost layers of a star form the star’s atmosphere. The layers exist in the following order (moving outward): the photosphere,
the chromosphere, and corona.
a. The photosphere has sunspots, which are areas of strong magnetic activity that are dark because they are cooler than the rest of the
photosphere.
b. A(n) prominence, which is a cloud of gas that loops into the corona, can last for weeks.
c. A(n) flare is a bright, violent eruption that can last for minutes or hours.
d. Coronal mass ejections, or CMEs, are huge bubbles of gas flung out from the corona that can reach beyond Earth and can disrupt
radio signals on Earth.
e. The solar wind is made up of charged particles that stream away from the Sun.
C. Classifying Stars
2. A star’s color is usually related to the star’s temperature.
a. Red stars are the coolest stars, and blue stars are the hottest.