THE ATOM

Question 1

postulated that all matter is made up of small indestructible units called atoms

Answer 1

Democritus
400BC

Question 2

proposed the atomic theory

Answer 2

John Dalton
1808

Question 3

the atomic theory

Answer 3

1. Elements are composed of extremely small particles called atoms.
2. All atoms of a given element are identical, having the same size, mass, and
   chemical properties. The atoms of one element are different from the atoms of
   all other elements.
3. Compounds are composed of atoms of more than one element. In any compound,
   the ratio of the numbers of atoms of any two of the elements present is either an
   integer or a simple fraction.
4. A chemical reaction involves only the separation, combination, or rearrangement
   of atoms; it does not result in their creation or destruction.

Question 4

states that different samples of the same
compound always contain its constituent elements in the same proportion by mass.

Answer 4

law of definite proportions

Question 5

if two elements can combine to form more than
one compound, the masses of one element that combine with a fi xed mass of the other
element are in ratios of small whole numbers.

Answer 5

law of multiple proportions

Question 6

matter can be neither created nor destroyed.

Answer 6

law of conservation of mass

Question 7

created the periodic table and discovered that the properties of elements are periodic functions of their atomic weights

Answer 7

Dmitri Mendeleev
1869

Question 8

proposed the theory of electromagnetism and established the connection between light and electromagnetic waves

Answer 8

James Clerk Maxwell
1873

Question 9

proposed that electricity is made up of discrete negative particles, which he called electrons

Answer 9

George Stoney
1874

Question 10

conducted experiments with cathode ray tubes; cathode rays carry a negative electric charge

Answer 10

Sir William Crookes
1879

Question 11

used cathode ray tubes to study canal rays; having both electrical and magnetic properties opposite to those of an electron

Answer 11

Eugene Goldstein
1886

Question 12

discovered that certain materials glowed when exposed to cathode rays and names these X-rays

Answer 12

Wilhelm Roentgen
1895

Question 13

discovered radiation by studying the effects of uranium on photographic film

Answer 13

Henri Becquerel
1896

Question 14

discovered alpha, beta, and gamma rays

Answer 14

Ernest Rutherford
1898

Question 15

used cathode ray tubes to determine the charge-to-mass ratio of the electron

Answer 15

Sir Joseph Thomson
1897

Question 16

theorized that radio active particles cause atoms to break down; releasing radiation in the form of energy

Answer 16

Pierre and Marie Curie
1898

Question 17

they discovered radioactive elements: polonium and radium

Answer 17

Pierre and Marie Curie
1898

Question 18

proposed the idea of how quantization to explain how a hot, glowing object emits light

Answer 18

Max Planck
1900

Question 19

discovered that there appeared to be more than one element at certain positions on the periodic table

Answer 19

Frederick Soddy
1900

Question 20

coined the term “isotope”

Answer 20

Margaret Todd
1900

Question 21

discovered that noble gases have stable electron configurations

Answer 21

Richard Abegg
1904

Question 22

developed the theories of relativity and hypothesized about the particle nature of light

Answer 22

Albert Einstein
1905

Question 23

invented a device capable of detecting alpha particles

Answer 23

Hans Geiger
1906

Question 24

determined the charge of the electron through his oil drop experiment

Answer 24

Robert Millikan
1909

Question 25

conducted the alpha particle experiment and established that the nucleus was very dense, very small, and positively charged

Answer 25

Ernest Rutherford 1911

Question 26

determined the Bohr atomic model: electrons traveling in orbits around the nucleus

Answer 26

Neils Bohr 1913

Question 27

discovered that the number of protons in an element determines its atomic number

Answer 27

Henry Moseley 1913

Question 28

proposed that the electrons exhibit wave-particle duality

Answer 28

Lous de Broglie 1924

Question 29

developed the Schrodinger equation: describing how the quantum state of a system changes over time

Answer 29

Erwin Schrodinger 1925

Question 30

father of modern chemistry; successfully explained combustion

Answer 30

Antoine Lavoisier

Question 31

proposed the law of definite proportions

Answer 31

Joseph Proust

Question 32

cathode ray tube experiment: determine the ratio of electric charge to the mass of an individual electron

Answer 32

J.J. Thomson

Question 33

oil drop experiment: charge of electron was exactly the same

Answer 33

Robert Millikan

Question 34

Plum Pudding Model

Answer 34

J.J Thomson

Question 35

describe the plum pudding model

Answer 35

an atom could be thought of as a uniform, positive sphere of matter in which electrons are embedded like raisins in a cake

Question 36

gold foil experiment

Answer 36

Ernest Rutherford

Question 37

Nuclear Model

Answer 37

Ernest Rutherford

Question 38

describe the Nuclear Model

Answer 38

atoms contain a tiny dense, positively charged nucleus

Question 39

Bohr's Planetary Model

Answer 39

depicts atoms having small positively charged nuclei surrounded by electrons in circular orbits

Question 40

discovered the neutron

Answer 40

James Chadwick

Question 41

the problem with the Bohr model

Answer 41

only for Hydrogen-like atoms

Question 42

tried to group the elements as metals and nonmentals

Answer 42

Antoine Lavoisier

Question 43

arranged in groups of three in increasing order of atomic weight

Answer 43

Johann Wolfgang Döbereiner 1829

Question 44

Law of Triads

Answer 44

Johann Wolfgang Döbereiner 1829

Question 45

Law of octaves - every 8th element exhibits similar properties when arranged by atomic weight

Answer 45

John Newlands 1863

Question 46

recognized the periodic behavior and repeating patters among elements. studied the atomic volume and relative atomic mass relationship

Answer 46

Lothar Meyer 1864

Question 47

formulated the periodic law

Answer 47

Dmitri Mendeleev 1869

Question 48

states that the properties of the elements are the periodic functions of their atomic masses

Answer 48

periodic law

Question 49

discovered that the wavelengths of X-ray emissions from elements corresponded to their atomic number; organize elements by virtue of atomic number; atomic number increases with atomic mass

Answer 49

Henry Moseley 1913

Question 50

discovered 10 transuranium elements; actinide series

Answer 50

Glenn Seaborg

Question 51

elements named after a living persons

Answer 51

Yuri Oganessian and Glenn Seaborg

Question 52

Electrical charge of a NEUTRON

Answer 52

+1.6022 x 10^(-19) C

Question 53

Electrical charge of an ELECTRON

Answer 53

-1.6022 x 10^(-19) C

Question 54

Electrical charge of a PROTON

Answer 54

0 C

Question 55

Mass of a NEUTRON (SI)

Answer 55

1.6726 x 10^(-24) g

Question 56

Mass of a NEUTRON (amu)

Answer 56

1.0073 amu

Question 57

Mass of a PROTON (SI)

Answer 57

1.6749 x 10^(-24) g

Question 58

Mass of a PROTON (amu)

Answer 58

1.0087 amu

Question 59

Mass of an ELECTRON (SI)

Answer 59

9.1094 x 10 ^(-28) g

Question 60

Mass of an ELECTRON (amu)

Answer 60

0.00054858 amu

Question 61

the number of neutrons is called the

Answer 61

atomic number (Z)

Question 62

the total number of protons and neutrons in an atom is called the

Answer 62

atomic mass/mass number (A)

Question 63

atoms of an element that have the same number of protons and the same number of electrons but different numbers of neutrons.

Answer 63

isotopes

Question 64

Same Z, Diff A

Answer 64

isotopes

Question 65

is the calculated average mass for the isotopes of an element, expressed on a scale where exactly 1/12 of the mass of Carbon-12

Answer 65

atomic mass unit (amu)

Question 66

states that when elements are arranged in order of increasing atomic number, elements with similar chemical properties occur at periodic (regularly) intervals.

Answer 66

periodic law