Reading 1.1-1.6

Question 1

viewed at the particle level, graphene consists of

Answer 1

sheets of carbon atoms bonded together

Question 2

When was graphene discovered

Answer 2

recently, but carbon networks like those in its structure have existed in nature for billions of years

Question 3

Modern scientists can characterize the properties of graphene because they

Answer 3

understand the carbon–carbon bonds that form its structure

Question 4

silicon wafers are widely used to make

Answer 4

computer chips and photovoltaic cells for solar panels

Question 5

Since the 1980s, scientists have been able to image individual atoms by using an instrument called a

Answer 5

scanning tunneling microscope (STM)

Question 6

atomism

Answer 6

• a belief that all forms of matter are composed of extremely tiny, indestructible building blocks called atoms
• spoused by Greece philopshers

Question 7

Atomism is an example of a ____. It is not a _____

Answer 7

natural philosophy, scientific theory

Question 8

The difference between the two is that although both seek to ____, scientific theories do so through…

Answer 8

• explain natural phenomena

- scientific theories do so through concise, testable explanations based on observation and experimentation

Question 9

published the first modern chem textbook in 1789. What did this book contain?

Answer 9

• French chemist Antoine Lavoisier

- a list of substances that he believed could not be seperated into simpler substances (which today we call elements)

Question 10

a concise and generally applicable statement of a fundamental scientific principle

Answer 10

scientific laws

Question 11

When French chemist Joseph Louis Proust studied the composition of compounds containing different metals and oxygen, he concluded…

Answer 11

that those compounds contained the same proportions of their compound elements always

Question 12

law of definite proportions

Answer 12

the principle that a compound always contains the same proportion of its component elements

Question 13

law of constant composition

Answer 13

the principle that all samples of a given compound have the same elemental composition by mass no matter what its source

Question 14

t/f the composition of water is always the same

Answer 14

true 11.2% by mass hydrogen and 88.6% by mass oxygen

Question 15

two principal categories of matter

Answer 15

pure substance and mixtures

Question 16

Scientific laws and theories complement each other in that scientific laws describe ____ and _____. and scientific theories explain…

Answer 16

• natural phenomena and relationships

- why those relationships are always observed

Question 17

t/f Scientific theories usually start out as tentative explanations of why a set of experimental results was obtained or why a particular phenomenon is consistently observed. Such a tentative explanation is called a hypothesis.

Answer 17

t

Question 18

proposed a scientific theory explaining Proust’s law of definite proportions

Answer 18

John Dalton
-observed that when two elements react to form gaseous compounds they may form two or more compounds with dif compositions. Dalton’s findings with gasous compounds agreed with findings from Proust’s experiments with solid compounds

Question 19

Dalton realized that the ratio of oxygen to tin in the second compound was

Answer 19

very close to twice what it was in the first compound

Question 20

To explain the laws of definite proportions and multiple proportions, Dalton proposed the scientific theory that

Answer 20

elements are composed of atoms

Question 21

COAST acronym mean

Answer 21

C collect 
O organize 
A analyze
S solve 
T think about it

Question 22

pure substances

Answer 22

the simplest forms of matter - elements and compounds (cannot be seprated into simpler substances by any physical process

Question 23

physical process

Answer 23

a transformation of a sample of matter such as a change in its physical state that does not alter the chemical identity of any substance in the sample
-also called physical change

Question 24

Pure substances have ___ properties

Answer 24

distinctive

Question 25

malleable

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can be hammered into very thin sheets called gold leaf

Question 26

ductile

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can be drawn into thin wires

Question 27

a property that is independent of the amount of substance

Answer 27

intensive properties

Question 28

a property that varies with the amount of substance; depend on how much the substance is present in a particular sample

Answer 28

extensive property

Question 29

density formula

Answer 29

m/v

Question 30

Which properties of a sample of pure iron are intensive? Which properties of a sample of pure iron are extensive?

Answer 30

- Mass and volume are extensive | - density and hardness are intensive

Question 31

monatomic

Answer 31

single-atom

Question 32

ions

Answer 32

a particle consisting of one or more atoms that has a net positive or net negative charge

Question 33

immiscible liquids

Answer 33

do not dissolve in each other

Question 34

distillation

Answer 34

- a component of the mixture (water) is separated by evaporation, and the resulting vapor is recovered by condensation - works as a separation technique whenever the individual components of a mixture have a different volatility -that is, one or more of them vaporizes more readily than the others

Question 35

volatility

Answer 35

-a measure of how readily a substance evaporates

Question 36

the volatility of a substance is inversely proportional to the ____.

Answer 36

- strength of the interactions between its particles - as the strength of interactions increases, the probability decreases that particles of the substance will have enough energy to break away from adjacent particles in the liquid phase and become particles of vapor

Question 37

filteration

Answer 37

the process of seperating solid particles from a liquid or gaseous sample by passing the sample through a porous material that retains the solid particles

Question 38

chromatography

Answer 38

a process for separating solid particles from a liquid or gaseous sample by passing the sample through a porous material that retains the solid particles

Question 39

chromatographic separation

Answer 39

the components of a liquid or gasous mixture are distributed between two phases a stationary solid (or liquid-coated solid) and a moving liquid or gas - the more strongly the particles in the ,obile phase interact with the stationary solid, the more slowly they move - those particles that interact weakly with the stationary solid move more rapidly

Question 40

Which physical process-distilation, filteration, or chromatography would you use to perform each of these separations a. removing particles of rust from drinking water - seperating the different coloring agents in a sample of ink c. seprating volatile compounds normally found in natural gas that have dissolved in a sample of crude oil

Answer 40

a filteration b chromatography c distillation

Question 41

is a wooden bat a pure substance

Answer 41

no

Question 42

has a definite volume and shape

Answer 42

solid

Question 43

has a definite volume but not a definite shape

Answer 43

liquid

Question 44

neither a definite volume nor a definite shape

Answer 44

gas

Question 45

each water molecule is surrounded by four others and locked in place in a hexagonal array of molecules that extends in all three spatial dimensions. Molecules in the array may vibrate a little, depending on their temperature, but they do not... Thus, ice is rigid at both the _____ and _____ levels.

Answer 45

- move past the molecules that surround them | - molecular, macroscopic

Question 46

Ice is rigid at both the ____ and ____ levels. The molecules in liquid water by contrast are more...

Answer 46

- molecular and macroscopic - randomly ordered and flow past one another - they are still close to each other but their nearest neighbors change over time

Question 47

sublimation

Answer 47

solid to gas

Question 48

solid to liquid

Answer 48

melting

Question 49

vaporization

Answer 49

liquid to gas

Question 50

liquid to solid

Answer 50

freezing

Question 51

gas to liquid

Answer 51

condensation

Question 52

gas to solid

Answer 52

deposition

Question 53

energy is defined as

Answer 53

the capacity to do work

Question 54

work is defined as and formula

Answer 54

- the exertion of a force through distance | - 1=F*d

Question 55

the chemical energy stored in glucose is an example of what kind of energy

Answer 55

potential energy (PE)

Question 56

the energy stored in an object because of its position or composition

Answer 56

potential energy (PE)

Question 57

the energy of motion

Answer 57

kinetic energy

Question 58

kinetic energy formula

Answer 58

- KE=1/2 mu^2 | - the product of the mass of the object (m) and the square of its speed (u)

Question 59

heat define

Answer 59

the transfer of energy that takes place because of a difference in temperatures

Question 60

law of conservation of energy

Answer 60

the principle that energy cannot be created or destroyed but can change from one form to another

Question 61

If the speed of a vehicle increases by 22%, by what factor does its kinetic energy increase?

Answer 61

KE=1/2mv^2 =1/2m1.22^2 =1.4884 KE =1.49 or 49%

Question 62

diatomic molecules

Answer 62

two-atom molecules

Question 63

molecular formula

Answer 63

- a chemical formula that indicates how many atoms of each element are in one molecule of a pure substance - indicate how many atoms of each element are present in one molecule of the compound

Question 64

structural formula

Answer 64

a representation of a molecule that uses short lines between the symbols of elements to show chemical bonds between atoms

Question 65

condensed structural formulas

Answer 65

- omit common structural components, such as C─H bonds or C atoms bonded to other C atoms - ex: the structural formula of acetic acid shows that 3 of the 4 H atoms are bonded to the same carbon atom - The same information is conveyed in the condensed structural formula by grouping three H atoms before the first C atom in the formula (H3C–).

Question 66

Ball-and-stick models

Answer 66

- 3D representations ofd molecules - use balls to represent atoms and sticks to represent chemical bonds - acccurately show the angles between the bonds in a molecule, but sticks make the atoms seem far apart when they actually overlap

Question 67

Space-filling models

Answer 67

-more accurately show how the atoms are arranged in a molecule and its overall 3D shape, but seeing all the atoms and the angels between the bonds is sometimes hard, especially in molecules with many atoms

Question 68

molecular formula of compound methanol

Answer 68

CH4O or CH3OH

Question 69

ionic compound

Answer 69

a compound that consists of a characteristic ratio of positive ions and negative ions

Question 70

a chemical formula in which the subscripts represent the simplist whole-# ratio of the atoms or ions in a compound

Answer 70

empirical formula