Exam 1 (Ch 1 & 2)

Question 1

Observing and understanding the natural

world

Answer 1

Science

Question 2

The study of universal phenomena

Answer 2

Physics

Question 3

4 steps of how science operates

Answer 3

Observe
Hypothesize
Test
If the hypothesis works, it is promoted to theory (a theory should predict phenomena that have not been observed yet)

Question 4

Study of stars and other objects in space

Answer 4

Astronomy

Question 5

“Physics” could best be described as the study of

Answer 5

The general principles underlying natural phenomena

Question 6

Each sphere rotates at a uniform rate around Earth, roughly once a day. So the planets go in simple circles around the Earth

Answer 6

Greeks

Question 7

Pythagoreans formed a cult that believed in the importance of abstract ideas -> mathematics
It was later observed that planetary motions are irregular and included retrograde motion. The theory was revised. Epicycles were added.

Answer 7

Pythagoras

Question 8

Earth is spherical:
Ships appear sink little by little below the horizon as they travel out to sea as seen by someone on land
Noontime Sun was lower in the sky in northern lands
Shadow of the Earth on the Moon during a lunar eclipse was round

Answer 8

Aristotle

Question 9

Sun at Center of Universe and other objects move around the sun in simple circles -> it was dismissed at the time

Answer 9

Aristarchus’ theory

Question 10

Planets move in circles within circles (loop-the-loops) around Earth

Answer 10

Epicycle theory

Question 11

Modified epicycle theory

His theory had > 80 epicycles

Answer 11

Ptolemy

Question 12

Planets moved in simple circles around the sun and explained retrograde motion
A sun-centered universe
Once Galileo had used the telescope to observe the
heavens, he was able to observe the phases of Venus. These phases are totally incompatible with the earth-centered universe

Answer 12

Copernicus’s theory

Question 13

The planet appears to move backwards on the sky as Earth overtakes the planet in its orbit. The apparent motion is caused by our line of sight to the planet changing. Planets appear brighter during this time since they are closer to us
Occurs when Earth overtakes another planet

Answer 13

Retrograde motion

Question 14

After 20 years of observations, he found that neither Ptolemy nor Copernicus was right
Johannes Kepler was his disciple

Answer 14

Tycho Brahe

Question 15

The orbital paths of the planets are elliptical (not circular) with the Sun at one focus
Each planet moves in an elliptical orbit around the sun with the sun occupying one foci of the ellipse (the other one is empty)

Answer 15

Kepler’s First Law

Question 16

(Addressing the speed of a planet along it’s elliptical path) An imaginary line connecting the Sun to any planet sweeps out equal areas of the ellipse in equal intervals of time. Planet moves faster when closer to the Sun
The imaginary line connecting the planet to the sun sweeps out equal areas in equal times

Answer 16

Kepler’s Second Law

Question 17

The square of any planet’s period of revolution is proportional to the cube of its mean distance from the sun
P2(in Earth years) = a3(in astronomical units)

Answer 17

Kepler’s Third Law

Question 18

What is the eccentricity of a circle?

Answer 18

0

Question 19

What is the eccentricity of a line?

Answer 19

1

Question 20

The average distance between Earth and the Sun

Answer 20

Astronomical unit

Question 21

A circle can be defined as the set of all points that are equidistant from the center point; all the points are the length of the radius away from the center
The separation of the two foci determines the eccentricity (or “out of round”) of this

Answer 21

Ellipse

Question 22

Point of closest approach of a planetary orbit

Answer 22

Perihelion

Question 23

Point at the greatest distance from the sun of a planetary orbit

Answer 23

Aphelion

Question 24

Why do the seasons come about?

Answer 24

The seasons come about because of the tilt of the axis about which the Earth rotates every 24 hours. The tilt is about 23.5 degrees

Question 25

The force, Fg, between two masses is proportional to the product of the masses and inversely proportional to the square of the distance between them. Mathematically: Fg = (constant) x (m1 * m2)/r2 Sir Isaac Newton

Answer 25

The Law of Gravitation

Question 26

Why does the sun wobble and what does the wobbling identify?

Answer 26

Our Sun wobbles because of the influence of the planets’ gravitational pull. This “wobbling” is one way there is to identify the presence of planets orbiting around other stars. If the orbit of a star wobbles, there must be planets

Question 27

5 things we know today

Answer 27

Rejection of the geocentric illusion that Earth is at the center of the universe The sun is just one star out of a large number of stars There are 400 billion “visible” gigantic groups of stars Each of the gigantic groups of stars is called a galaxy Ours is the Milky Way; we are located about 2/3 of the way out from the center

Question 28

General behavior not directly compared to actual | measurements (numbers)

Answer 28

Qualitative

Question 29

Measurements that compare numbers | calculated from a theory to numbers measured through experiment

Answer 29

Quantitative

Question 30

Data-gathering

Answer 30

Observation

Question 31

Quantitative observation

Answer 31

Measurement

Question 32

Observation designed and controlled by humans

Answer 32

Experiment

Question 33

Confirmed framework of ideas that explains or unifies a group of observations

Answer 33

Theory

Question 34

Theory that can be visualized

Answer 34

Model

Question 35

Is any scientific idea ever certain?

Answer 35

No

Question 36

The most significant difference between the astronomical theories of Ptolemy and Copernicus

Answer 36

Ptolemy's theory is Earth-centered, whereas Copernicus's is sun-centered

Question 37

The closest planet to the sun

Answer 37

Mercury

Question 38

Which statement best describes the status of the Copernican and Ptolemaic theories of the solar system shortly after Copernicus invented his theory and before Tycho Brahe made his observations?

Answer 38

Both theories agreed with the experimental facts

Question 39

Which of the following statements best describes the status of Copernican and Ptolemaic theories of the solar system shortly after Tycho Brahe's observations? (a) These observations showed Ptolemy's theory to be the correct one (b) These observations showed Copernicus's theory to be the correct one (c) These observations showed both theories to be correct (d) These observations showed both theories to be incorrect (e) These observations turned out to have little or no bearing on either theory

Answer 39

(d) These observations showed both theories to | be incorrect

Question 40

All matter is made of tiny particles too small to be seen (Democritus)

Answer 40

The atomic theory of matter

Question 41

The erratic motion of a microscopic dust or pollen grain immersed in a liquid or gas, caused by numerous moving atoms or molecules colliding with the grain every second

Answer 41

Brownian motion

Question 42

What is all matter made from?

Answer 42

Atoms

Question 43

Process of breaking down a substance into two or more simpler substances using chemical reactions

Answer 43

Chemical decomposition

Question 44

``` Some substances (about 100) cannot chemically decomposed into any simpler substances. Examples: hydrogen, helium, oxygen, sodium, neon... Symbolized by either one or two letters on the periodic table ```

Answer 44

Chemical elements

Question 45

Any pure substance made of atoms of different types. Examples: water, carbon dioxide, sodium chloride...

Answer 45

Chemical compound

Question 46

The smallest single unit of a chemical compound

Answer 46

Molecule

Question 47

A fundamental orienting concept that helps chemists organize their observations; helped make predictions for the properties of elements that were yet to be discovered

Answer 47

Periodic table

Question 48

Represent chemical compounds; consists of the symbols of the elements that constitute the molecule, sub-indexed by the number of atoms of each type present in the molecule (if the subindex is 1, it is omitted). Ex: a water molecule contains two hydrogen atoms and one oxygen atom, it is symbolized by H2O

Answer 48

Chemical formulas

Question 49

Horizontal lines in the periodic table Plotting properties as a function of the atomic number we'd notice that they group themselves up into separate and distinct sets One includes just hydrogen and helium, the next goes from Lithium to neon, the following one from sodium to argon, etc.

Answer 49

Periods

Question 50

Vertical columns in the periodic table Columns in the periodic table provide a more detailed classification of the elements according to their properties All the elements in this have properties similar to each other

Answer 50

Groups

Question 51

How many periods and groups are there in the periodic table?

Answer 51

There are 7 periods and 18 groups in the periodic table

Question 52

Have a self-defined volume and shape Atoms are locked in their positions Difficult to compress

Answer 52

Solids

Question 53

Have a self-defined volume but take on the shape of the container that holds them Difficult to compress Atoms in them must be packed in pretty close Flow (atoms can slide past each other)

Answer 53

Liquids

Question 54

Take both the shape and volume of their container Easily compressed which means that the atoms are not tightly packed Atoms can move around

Answer 54

Gases

Question 55

The atom is a small indivisible particle like a solid sphere

Answer 55

Greek model of the atom

Question 56

J.J. Thomson: the atom is composed of a positive jelly-like substance in which the negatively charged electrons are embedded

Answer 56

Plum pudding model of the atom

Question 57

This was, as Rutherford said, like shooting cannonballs at tissue paper and finding that some of the cannonballs bounced back at you Led Ernest Rutherford to develop the planetary model of the atom

Answer 57

Rutherford's gold foil experiment

Question 58

In this model most of the atom is just empty space | There is a massive, positively charged center (the nucleus with protons and neutrons) and the electrons orbit around it

Answer 58

Planetary model

Question 59

4 facts of electric charge

Answer 59

It comes it two types: positive and negative Net charge is conserved Like charges repel, opposite charges attract It only comes in discrete amounts (the smallest amount possible is the amount that comes with an electron)

Question 60

Since the atom is neutral, the number of electrons | orbiting the nucleus must be what compared to the number of protons in the nucleus?

Answer 60

The same

Question 61

An atom that carries a net charge, has either an excess or a deficiency in the number of electrons it contains

Answer 61

Ion

Question 62

Composed of two types of objects: protons and neutrons

Answer 62

Nucleus

Question 63

What protons and neutrons are collectively called

Answer 63

Nucleons

Question 64

The number of protons in the nucleus; if the atom is neutral (not an ion), then this is also the number of electrons orbiting the nucleus

Answer 64

Atomic number (Z)

Question 65

Atoms with the same number of protons but a different number of neutrons, still the same element

Answer 65

Isotope

Question 66

What was the fundamental flaw of the planetary model of the atom?

Answer 66

Moving electric charges must emit electromagnetic radiation; a charge emitting electromagnetic radiation looses energy

Question 67

The electrons can only occupy specific orbits Each orbit has a maximum number of electrons that it can hold due to the Pauli exclusion principle The outermost/valence electrons determine the chemical properties, all the elements in a group have the same number of valence electrons

Answer 67

The ("old") quantum model of the atom/Bohr's model

Question 68

The negative charge the electrons carry looks smeared out (like a cloud)

Answer 68

The modern quantum description of the atom

Question 69

How do we write 1,200,000,000,000,000,000 in scientific notation?

Answer 69

1.2 x 10^18 | There are 18 spots after the first number but we have to account for the 2

Question 70

What is 0.00000000000051 in scientific notation?

Answer 70

5.1 x 10^-13 | There are 13 digits from the decimal point to the 5 including the 5

Question 71

Which ancient Greek proposed a sun-centered theory?

Answer 71

Aristarchus

Question 72

When Earth overtakes another planet in its orbit and the other planet appears to move backwards for a time, what is the apparent motion called?

Answer 72

Retrograde motion

Question 73

Who originated the idea that planets go in ellipses around the sun?

Answer 73

Kepler

Question 74

By noting that ships drop below the horizon as they go out to sea, ancient Greeks such as Aristotle knew what?

Answer 74

The earth was round

Question 75

Who observed the phases of Venus and showed that they were incompatible with an Earth-centered universe?

Answer 75

Galileo

Question 76

Who made very accurate measurements that contradicted both Ptolemy’s theory and Copernicus’s theory?

Answer 76

Tycho Brahe

Question 77

A sulfur atom weighs twice that of an oxygen atom. What is the ratio of the weight of sulfur to oxygen in sulfur dioxide, SO2?

Answer 77

1 to 1

Question 78

How many atoms are in a molecule of sugar, C6H12O6?

Answer 78

24

Question 79

According to the planetary model an atom is what?

Answer 79

Made of protons, electrons, and neutrons

Question 80

What are atoms?

Answer 80

Mostly empty space

Question 81

Who discovered the nucleus by bombarding a piece of gold foil with alpha particles?

Answer 81

Ernest Rutherford

Question 82

The radius of the Earth at the equator is about 6400 km. What is this expressed in scientific notation?

Answer 82

6.4 x 10^3 km