Chemistry Chapter 1-4 Test

Front 1

What is chemistry?

Back 1

the science that seeks to understand what matter does by studying what atoms and molecules do

Front 2

what is the scientific method?

Back 2

a way of learning that emphasizes observation and experimentation to understand the world

Front 3

what are the steps of the scientific method?

Back 3

1.observation
2.hypothesis
3.experimentation
4.theory
5. law

Front 4

what is observation?

Back 4

-an observation must measure or describe something in the physical world.
-observing the trend/patterns

Front 5

what is hypothesis?

Back 5

a tentative interpretation or explanation for an observation that can be tested by further investigation

Front 6

what is experimentation?

Back 6

-highly controlled ovbservations designed to validate or invalidate the hypothesis.
-CONTROL VARIABLES

Front 7

what is a theory?

Back 7

-provides a broader and deeper explanation for observations and laws
-tells you what happened and why

Front 8

what is a law?

Back 8

-a statement that summarizes past observations and predicts future ones
-formed from a series of related observations

Front 9

what is matter?

Back 9

anything that occupies space and has mass

Front 10

what is a pure substance?

Back 10

1.atoms
2.molecules/compounds

Front 11

what is a homogeneous mixture?

Back 11

1.same elements(composition is the same throughout)
2.aka solution

Front 12

what is a heterogeneous mixture?

Back 12

1.different elements (composition varies from one region to another)

Front 13

what is the difference between an observation and a law?

Back 13

observation: trends and patterns
law: summary of observation

Front 14

what is the difference between a hypothesis and a theory?

Back 14

hypothesis: educated guess explaining the observation
theory: explaining the observation thats been PROVEN

Front 15

what is the difference between a law and a theory?

Back 15

law: tells us what
theory: tells us why

Front 16

what is the law of conservation of mass?

Back 16

a law stating that in a chemical reaction, matter is neither created nor destroyed

Front 17

what is atomic theory?

Back 17

a theory stating that all matter contains tiny particles called atoms.

Front 18

what are the two properties of matter?

Back 18

1. physical properties
2.chemical properties

Front 19

what defines physical properties? what are some examples?

Back 19

-can be observed without changing a substance into another substance
ex: boiling point, density, mass, vol.

Front 20

what defines chemical properties? what are some examples?

Back 20

-can only be observed when a substance is changed into another substance
ex: flammability, corrosivemess, reactivity with acid

Front 21

does the synthesis of a pure substance use physical or chemical properties to produce more compound?

Back 21

chemical

Front 22

what classifies matter?

Back 22

-solid
-liquid
-gas

Front 23

homogeneous and heterogeneous substances are what?

Back 23

mixtures

Front 24

atoms and molecules/compounds are what?

Back 24

pure substances

Front 25

what is matter divided into?

Back 25

mixtures and pure substances

Front 26

a solution contains what two parts?

Back 26

1. solute :minor component
2.solvent:majority component usually H2O

Front 27

what is a measurement

Back 27

-quantitative observation with a number and a unit
-comparison to an agreed upon standard

Front 28

what is a significant figure

Back 28

writing numbers to reflect precision whenever you use an instrument to compare a quality of an object to a standard.
-where there is uncertainty in the comparison

Front 29

what is an exact number

Back 29

-during couting (3 pennies)
-in definition (1 ounce=1/16 of 1 pound)

Front 30

what is the estimated number in a measurement?

Back 30

the last digit of the number

Front 31

what are the 5 rules of sig. figs.?

Back 31

1. all non zero digits are significant
2.interior zeros are significant
3.trailing zeros after the decimal point are significant
4.leading zeros are NOT signifcant
5.zeros at the end of a number without a written decimal point should be written in scientific notation. (150=1.5 X 10^2)

Front 32

how many sig figs do exact numbers have?

Back 32

unlimited

Front 33

Mega=

Back 33

10^6 (1,000,000)

Front 34

Kilo=

Back 34

10^3 (1000)

Front 35

Deci=

Back 35

10^-1 (0.1)

Front 36

Centi=

Back 36

10^-2 (0.01)

Front 37

Milli

Back 37

10^-3 (0.001)

Front 38

Micro

Back 38

10^-6 (0.000001)

Front 39

Nano

Back 39

10^-9 (0.000000001)

Front 40

what is the formula for density?

Back 40

D=M/V

Front 41

what is the formula for Mass?

Back 41

M=DxV

Front 42

what is the formula for Volume?

Back 42

V=M/D

Front 43

the larger the density the...

Back 43

-larger the mass and the smaller the volume

Front 44

Define Matter

Back 44

anything that occupies space and has mass
composed of atoms and molecules

Front 45

What are the three phases of matter?

Back 45

1.solid
2.liquid
3.gas

Front 46

Define a solid

Back 46

has fixed volume and shape

Front 47

Define a gas

Back 47

always fills up the container and changes its shape with the container

Front 48

Define a liquid

Back 48

has fixed volume but changes shape with container

Front 49

explain the interaction of molecules within a solid, liquid, and gas

Back 49

solid=strong interaction b/t molecules
liquid=fixed interaction b/t molecules
gas=weak interaction b/t molecules

Front 50

define crystalline solids

Back 50

-some solids have their particles arranged in an orderly geometric pattern
(salt and diamonds)

Front 51

define amorphous solids

Back 51

other solids have particles that do not show a regular geometric patter over a long range
(plastic, glass)

Front 52

define two different types of solids

Back 52

1.crystalline solids
2.amorphous solids

Front 53

define atoms

Back 53

the tiny particles that make up all matter and cannot be seperated chemically

Front 54

define molecules

Back 54

-the atoms are joined together in units called mollecules
-more than 2 atoms
-bound chemically, cannot be seperated physically

Front 55

how are the properties of matter determined?

Back 55

-by the atoms and molecules that compose it
-depends on the way molecules are arranged

Front 56

define a pure substance

Back 56

-always homogeneous
-matter that is composed of only one kind of atom/molecule
-all samples show the same properties

Front 57

define mixture

Back 57

-homogeneous or heterogeneous
-matter composed of different kinds of atoms/molecules
-different samples will show different properties

Front 58

what seperates in components based on chemical properties?

Back 58

pure substances

Front 59

what seperates into components based on physical properties?

Back 59

mixtures

Front 60

define element

Back 60

-substances that cannot be broken down into simpler substances by chemical reactions
-single type of atom

Front 61

define compound

Back 61

-substances that can be decomposed
-chemical combinations of molecules

Front 62

define homogeneous mixtures

Back 62

-mixtures that are uniform throughout
-aka solutions

Front 63

define heterogeneous mixtures

Back 63

-mixtures that have regions with different characteristics

Front 64

define physical properties

Back 64

the characterisitcs of matter that can be changed without changing its composition

Front 65

define chemical properties

Back 65

-the characterisitcs that determine how the composition of matter changes as a result of contact with other matter or the influence of energy

Front 66

define chemical changes
-give examples

Back 66

-the atoms that are present rearrange into new molecules, but all the original atoms are still present
-produce new material
(rusting of iron, burning, tarnish)

Front 67

define physical changes
-give examples

Back 67

-changes in the properties of matter that do not effect its composition
(heating water, evaporation, dissolving sugar in water, meltin, freezing, boiling)

Front 68

define the law of conservation of mass

Back 68

-Antoin Lavoisier
-"matter is neither created nor destroyed in a chemical reaction"
-total mass of all reactants=total mass of all the products

Front 69

define energy

Back 69

-Energy is anything that has the capacity to do
work.
-things that do not have mass and
volume.

Front 70

define the law of conservation of energy

Back 70

-"energy can neither be created nor destroyed"
-the total amount of energy in the universe is constant
-we can transfer energy from one place in the universe to another, and we can change its form

Front 71

what are the two types of energy

Back 71

1.potential energy
2.kinetic energy

Front 72

define potential energy

Back 72

-the energy that is stored

Front 73

define kinetic energy

Back 73

-the energy of motion, or energy that is being transferred from one object to another

Front 74

what is electrical energy

Back 74

kinetic

Front 75

what is heat/thermal energy

Back 75

kinetic

Front 76

what is light/radiant energy

Back 76

kinetic

Front 77

what is nuclear energy

Back 77

potential

Front 78

what is chemical energy

Back 78

potential

Front 79

define a Calorie(cal)

Back 79

the amount of energy needed to raise 1g of water by 1 degree celcius

Front 80

define kcal

Back 80

energy needed to raise 1000g of water by 1 degree celcius

Front 81

1cal= how many J

Back 81

4.184J

Front 82

1Cal=how many cal

Back 82

1000 cal

Front 83

1kwh=how many J

Back 83

3.60*10>6J

Front 84

what is chemical potential energy

Back 84

-the amount of energy stored in a material
-the attachments b/t atoms in the molecules
-the attractive forces b/t molecules

Front 85

when do chemical reactions happen

Back 85

they happen most readily when energy is released during the reaction

Front 86

are molecules with lots of chemical potential energy more stable or less stable than ones with less chem. pot. energy?

Back 86

less stable

Front 87

when the products chemical potential energy is greater than the reactants the chem. pot. energy is being

Back 87

absorbed

Front 88

when the products chemical pot. energy is less than the reactants the CPE is being

Back 88

released

Front 89

define exothermic processes:
-when does it occur
-where is the excess energy going

Back 89

-releasing energy
-occurs when the products have LESS chemical pot. energy than the reactants
-the excess energy is released into the surrounding materials, adding energy to it

Front 90

define endothermic processes
-when does it occur
-where is the required energy coming from

Back 90

-absorbing energy
-occurs when the products have MORE chem. potential energy than the reactants
-the required energy is absorbed from the surrounding materials, taking energy from them

Front 91

what is room temperature

Back 91

25 degrees celcius

Front 92

what is the absolute temperature

Back 92

kelvin

Front 93

what is the equation to convert celcius to fahrenheit

Back 93

F = (1.8 x C) + 32

Front 94

what is the equation to convert fahrenheit to celcius?

Back 94

C=5/9(F-32)

Front 95

what is the equation to convert from celsius to kelvin

Back 95

K=C+273

Front 96

what is the equation to convert kelvin to celsius

Back 96

C=K-273

Front 97

define heat capacity

Back 97

the amount of heat a substance must absorb to raise its temp. by 1 degree celsius

Front 98

what is the unit for heat capacity

Back 98

cal/degree c or J/degree c

Front 99

define specific heat

Back 99

heat capacity of 1g of the substance

Front 100

what is water's specific heat

Back 100

4.184 J/g degree c

Front 101

what is the unit for specific heat

Back 101

cal/g or J/g degree c

Front 102

define specific heat capacity

Back 102

-the amount of energy required to raise the temperature of 1 g of a substance by 1 degree celsius

Front 103

how many elements are found in nature

Back 103

91

Front 104

how many elements have been made in laboratories

Back 104

over 20

Front 105

Define Dalton's Atomic
(3)

Back 105

1.each element is composed of indestructable particles called atoms
2.all atoms of an element are identical
3.atoms combine in simple, whole number ratios to form molecules and compounds

Front 106

explain the amu vs. the gram
-when is each used

Back 106

-Dalton based his scale on H=amu
-gram is used per mole
-amu is used per atom

Front 107

what did J.J. Thomson find?

Back 107

found that electrons are much smaller than antoms and carry a neg. charge

Front 108

Define Thomson's method

Back 108

1. The atom is breakable.
2. The atom’s structure has electrons suspended in a
positively charged electric field.

Front 109

Define Rutherford's method

Back 109

1. The atom contains a tiny dense center
called the nucleus.
2. The electrons are dispersed in the empty space of the atom surrounding the nucleus.
3.there are as many neg. charged electrons outside the nucleus as there are positively charged protons inside the nucleus=making the atom neutral

Front 110

explain the plum pudding model by thomson

Back 110

negatively charged electrons were held in a sphere of positive charge

Front 111

explain the gold foil experiment done by rutherford

Back 111

-this proved thomson's method wrong
-he directed tiny positiveley charged particles called alpha particles through it and instead of all of them passing through, some of them deflected into different directions and some bounced back

Front 112

if an atom has 20 protons and 18 electrons what is its charge, what is its atomic #

Back 112

2+, 20

Front 113

define the atomic number

Back 113

the number of protons

Front 114

define mass number

Back 114

# of protons + # of neutrons

Front 115

6
C
12.00
what is its atomic # and what is its atomic mass

Back 115

atomic #=6
atomic mass=12.00

Front 116

define the scientific method development:
-periodic law?

Back 116

-mendeleev
-saw a repeated number of properties and ordered elements by atomic mass
-periodic law: when the elements are arranged in order of increasing relative mass, certain sets of properties recur periodically

Front 117

define metals

Back 117

-solid at room temp. (except mercury)
-reflective surface
-conduct heat and electricity
-malleable
-ductile
-los electrons to form cations

Front 118

define non metals

Back 118

-poor conductors of heat and electricity
-solids are brittle
-gain electronss in reactions to become anions
-upper right on periodic table

Front 119

define metalloids

Back 119

-show some properties of metals and some of non metals
-aka semiconductors

Front 120

are the following metals, nonmetals, or metalloids:
1.Xe
2.W
3.Br
4.As
5. Ce

Back 120

1.nonmetal
2.metal
3.nonmetal
4.metalloid
5.metal

Front 121

define columns of the periodic table

Back 121

-vertical rows(group or family)
-elements with similar chame/phys. characteristics are in the same column

Front 122

define rows of the periodic table

Back 122

-horizontal
-aka periods

Front 123

define main groups of the periodic table

Back 123

-representative elements=A

Front 124

define transition elements of the periodic table

Back 124

=B groups, all metals

Front 125

define bottom rows of the periodic table

Back 125

inner transition elements=rare earth elements
-metals

Front 126

define alkali metals

Back 126

-Group 1A
-soft low melting points, low density
-very reactive, never found uncombined in nature
-react with H2O to form proton

Front 127

define alkali earth metals

Back 127

-Group IIA
-harder, higher melting point, and denser than alkali metals

Front 128

define halogens

Back 128

-group VIIA
-nonmetals=form neg. ions
-all datomic
-VERY reactive
-react with metals to form ionic compounds

Front 129

define a gas, liquid, and solid form of a halogen

Back 129

gas=F2 and Cl2
liquid=Br2
solid=I2

Front 130

define noble gases

Back 130

-group VIIIA
-all gases at room temp
-very low melting point and boiling point
-very unreactive
-cery hard to remove electron from orfive electron to
-VERY STABLE

Front 131

define charges atoms

Back 131

-the # of protons determines the element
-in a chemical change, the number of protons in the nucleus of the atom does NOT change

Front 132

define ions

Back 132

ion charge=# of protons-#of electrons

Front 133

define cation

Back 133

-metals
-ions with a positive charge
-more protons then electrons by losing electrons

Front 134

define anion

Back 134

-non metals
-more electrons than protons by gaining electrons
-ions with a neg. charge
-named by changing the end to -ide

Front 135

what are the number of protons and electrons in Ca2+
if the atomic number is 20

Back 135

e=18
p=20
n=20

Front 136

define valence electrons

Back 136

-the highest energy electrons in an atom are called the valence electrons

Front 137

do non metas tend to have a neg. oxidation number are a positive

Back 137

neg. although some are post. in certain compounds or ions

Front 138

define isotope

Back 138

-same number of protons but diff. number of neutrons
-chemical property is the same
-

Front 139

define percent natural abundance

Back 139

relative amount found in the nature for that species

Front 140

how do you calculate avg. atomic mass?

Back 140

AAM=sum of atomic mass X relative natural abundance / 100

Front 141

how do you find the number of neutrons in an ion?

Back 141

=A-Z