Chapter 2

Question 1

Scanning tunneling microscopy (STM)

Answer 1

a technique that can image, and even move, individual atoms and molecules

Question 2

tunneling current

Answer 2

the electrical current that flows between the tip of the electrode and the surface even though the two are not in physical contact

Question 3

The smalles identifiable unit of an element

Answer 3

atom

Question 4

the law of conservation of mass

Answer 4

In a chemical reaction, matter is neither created nor destroyed

Question 5

Antoine Lavoisier formulated this law

Answer 5

the law of conservation of mass

Question 6

Joseph Proust observed this law

Answer 6

The law of definite proportions

Question 7

the law of definite proportions

Answer 7

All samples of a given compound, regardless of their source or how they are prepared, have the same proportions of their constituent elements

Question 8

John Dalton stated this law

Answer 8

the law of multiple proportions

Question 9

the law of multiple proportions

Answer 9

When two elements (A and B) form two different compounds, the masses of element B that combine with 1g of element A can be expressed as a ratio of small whole numbers.

Question 10

John Dalton stated this theory

Answer 10

atomic theory

Question 11

Atomic theory

Answer 11

1. each element is composed of tine, indestructible particles called atoms
2. all atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements
3. atoms combine in simple, whole-numbered ratios to form compounds
4. atoms of one element cannot change into atoms of another element.

Question 12

J.J. Thompson used this to discover electrons

Answer 12

cathode rays in a cathode ray tube

Question 13

electron

Answer 13

negatively charged, low mass partical present within all atoms

Question 14

electrostatic forces

Answer 14

electrical charge is a fundamental property of some of the particles that compose atoms and results in attractive and repulsive forces

Question 15

electric field

Answer 15

An area around a charged particle where electrostatic forces exist

Question 16

J.J. Thompson discovered this

Answer 16

Electrons

Question 17

Robert Millikan

Answer 17

discovered the charge of a single electron with his oil drop experiment

Question 18

Electron charge

Answer 18

-1.60 x 10^-19 C

Question 19

Electron mass

Answer 19

.00091 x 10^-27 kg

Question 20

Radioactivity

Answer 20

the emission of small energetic particles from the core of certain unstable atoms

Question 21

Henri Becquerel and Marie Curie discovered this

Answer 21

radioactivity

Question 22

Rutherford proposed this

Answer 22

nuclear theory, after completing his gold foil experiment

Question 23

nuclear theory states

Answer 23

1. Most of the atom’s mass and all of its positive charge are contained in a small core called the nucleus
2. most of the volume of the atom is empty space, throught which tine, negatively charged electrons are dispersed
3. there are as many negatively charged electrons outside of the nucleus as there are positively charged particals withing the nucleus, so the atom is electrically neutral

Question 24

neutrons

Answer 24

neutral particles withing the nucleus, with mass similar to a proton

Question 25

James chadwick found these

Answer 25

neutrons

Question 26

Atomic Mass Unit (AMU)

Answer 26

defined as 1/12 the mass of a carbon atom containing six protons and six neutrons

Question 27

proton mass

Answer 27

1.672 x 10^-27 kg

Question 28

proton charge

Answer 28

+1.602 x 10^-19 C

Question 29

neutron mass

Answer 29

1.674 x 10^-27 kg

Question 30

neutron charge

Answer 30

0

Question 31

Defines an element

Answer 31

the number of protons

Question 32

atomic number

Answer 32

the number of protons in an element

Question 33

chemical symbol

Answer 33

one or two letter abbreviation listed directly below its atomic number

Question 34

Elements chemical symbols and names come from

Answer 34

English names, latin names, names to reflect properties, and astronomical bodies, and scientist who discovered it

Question 35

Isotope

Answer 35

Atoms with the same number of protons but different numbers of neutrons

Question 36

Natural abundance

Answer 36

the percentage of the individual isotopes found in nature

Question 37

mass number

Answer 37

the sum of the number of neurons and protons in an atom

Question 38

Ions

Answer 38

When an atoms loses or gains and electron

Question 39

Cation

Answer 39

positively charged ion

Question 40

anion

Answer 40

negatively charged ion

Question 41

Dmitri Mendeleev

Answer 41

created the periodic table, and stated the periodic law

Question 42

periodic law

Answer 42

When elements are arranged in order of increasing mass, certain sets of properties recur periodically

Question 43

Classifications of elements in the periodic table

Answer 43

metals, nonmetals, metalloids

Question 44

metals

Answer 44

lie on the lower left side and middle of the periodic table and share some common properties. good conductors, malleability, ductility, often shiny, and tend to lose electrons when they undergo chemical changes

Question 45

nonmetals

Answer 45

lie on the upper right side of the periodic table. varied properties(solid, liquid, gas), tend to be poor conductors, and they tend to gain electrons when they undergo chemical changes.

Question 46

metalloids

Answer 46

lie alone the zigzag diagonal line that divides metals and nonmetals. exhibit mixed properties. some are classified as semiconductors

Question 47

semiconductors

Answer 47

The classification for several metalloids, because of their intermediat and highly temperature dependent electrical conductivity. the ability to change and control conductivity makes them useful in making electronic chips and circuits.

Question 48

main group elements

Answer 48

properties tend to be largely predictable based on their position in the periodic table. 1a-2a, 3a-8a

Question 49

transition elements or transition metals

Answer 49

properties tend to be less predictable based on their position in the periodic table. 3b-8b, 1b-2b

Question 50

family or group

Answer 50

each column within the main-group regions of the periodic table

Question 51

Noble gasses

Answer 51

mostly unreactive, 8a

Question 52

alkali metals

Answer 52

reactive metals, 1a

Question 53

alkaline earth metals

Answer 53

fairly reactive, although not as reactive as alkali metals, 2a

Question 54

halogens

Answer 54

very reactive nonmetals, 7a

Question 55

Predicting ions (2 ways)

Answer 55

1. main group metal tends to lose electrons, forming a cation with the same number of electrons as the nearest noble gas 2. main group nonmetals tend to gain electrons, forming an anion with the same number of elctrons at the nearest noble gas

Question 56

Atomic mass

Answer 56

calculation of the average mass of an element found by taking the percent natural abundance found of each isotope.

Question 57

Mole

Answer 57

the amount of a material containing 6.022 x 10^23 particles

Question 58

avogadros number

Answer 58

6.022 x10^23 particles,

Question 59

How does the mole get its specific value

Answer 59

the value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12

Question 60

1 mole = (particles, grams)

Answer 60

6.022 x 10^23 particles, atomic mass # of grams

Question 61

molar mass

Answer 61

an element's molar mass in grams per mole is numerically equal to the element's atomic mass in atomic mass units