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物質，元素，和原子
『從原子到宇宙』課程第二週
胡維平
國立中正大學化學暨生物化學系
9/27/2012
Aristotle
(384 BC-322 BC)
希臘
Aristotle believed that four
elements make up everything under
the moon (the terrestrial): earth, air,
fire and water. Different substances
are made from different
proportions of these elements.
Democritus
(460 BC-370 BC)
希臘
The theory of Democritus and Leucippus held that
everything is composed of "atoms", which are indivisible;
that between atoms lies empty space; that atoms are
indestructible; have always been, and always will be, in
motion; that there are an infinite number of atoms, and
kinds of atoms, which differ in shape, and size.
五行學說
中國傳統五行學說認為宇宙萬物，都由木火
土金水五種基本物質的運行（運動）和變化
所構成。中國西周末年，已經有了一種樸素
唯物主義觀點的五材說。從《國語‧鄭語》
「以土與金、木、水、火雜，以成萬物」和
《左傳》「天生五材，民並用之，廢一不可」
到《尚書‧洪範》「五行：一曰水，二曰火，
三曰木，四曰金，五曰土。水曰潤下，火曰
炎上，木曰曲直，金曰從革，土爰稼穡。潤
下作鹹，炎上作苦，曲直作酸，從革作辛，
稼穡作甘。」的記載，開始把五行屬性抽象
出來，推演到其他事物，構成一個固定的組
合形式。
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化學的起源 — 煉金術
Francis Bacon (1561-1626) : alchemy – vineyard story
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Robert Boyle
(1627-1691)
英國
元素的概念及氣體定律 (PV = constant)
1. Boyle is largely regarded today as the
first modern chemist, and therefore
one of the founders of modern
chemistry, and one of the pioneers of
modern experimental scientific
method.
2. He endorsed the view of elements as
the undecomposable constituents of
material bodies; and made the
distinction between mixtures and
compounds.
Antoine Lavoisier
(1743-1794)
法國
拉瓦錫 – 現代化學之父
Lavoisier: Conservation of Mass
Although matter might change its form during a
chemical reaction, it cannot be created or
destroyed – mass, and therefore matter, is
conserved.
Lagrange: "It took them only an instant to cut
off his head, but France may not produce
another such head in a century.")
John Dalton
(1766-1844)
英國
成熟的原子學說
1. Elements are made of extremely
small particles called atoms.
2. Atoms of a given element are
identical in size, mass, and other
properties; atoms of different
elements differ in size, mass, and
other properties.
3. Atoms cannot be subdivided, created,
or destroyed.
4. Atoms of different elements combine
in simple whole-number ratios to
form chemical compounds.
5. In chemical reactions, atoms are
combined, separated, or rearranged.
Dmitri Mendeleev
(1834-1907)
門德烈夫
俄國
週期表的創始人 (also Julius Lothar Meyer)
54 known elements in1864
元素之間的關聯?
元素發現的年代
門德烈夫對週期表德說明
On 6 March 1869, Mendeleev made a formal presentation to the Russian Chemical Society,
entitled The Dependence between the Properties of the Atomic Weights of the Elements
1. The elements, if arranged according to their atomic weight, exhibit an apparent periodicity
of properties.
2. Elements which are similar in regards to their chemical properties have atomic weights
which are either of nearly the same value (e.g., Pt, Ir, Os) or which increase regularly (e.g.,
K, Rb, Cs).
3. The arrangement of the elements in groups of elements in the order of their atomic weights
corresponds to their so-called valencies, as well as, to some extent, to their distinctive
chemical properties; as is apparent among other series in that of Li, Be, B, C, N, O, and F.
4. The magnitude of the atomic weight determines the character of the element, just as the
magnitude of the molecule determines the character of a compound body.
5. We must expect the discovery of many yet unknown elements–for example, two elements,
analogous to aluminium and silicon, whose atomic weights would be between 65 and 75.
(Ga: 70, Ge: 73)
6. Certain characteristic properties of elements can be foretold from their atomic weights.
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門德列夫的預測
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現代週期表
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Amedeo Avogadro
(1766-1844)
亞佛加厥
義大利
正確的分子學說
Amedeo Avogadro hypothesized in 1811 that two
given samples of an ideal gas, at the same temperature,
pressure and volume, contain the same number of
molecules. Thus, the number of molecules or atoms in
a specific volume of gas is independent of their size or
the molar mass of the gas.
He believed that gases are composed of molecules, and
these molecules are composed of atoms.
NA = 6.02214179(30)×1023 mol−1
Turin, Italy
Wilhelm C. Roentgen
(1845-1923)
Discovery of X-Ray
Nov. 8, 1895
Nobel Prize for Physics (1901)
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Henri Becquerel
Discovery of Radioactivity
Feb. 26, 1896
K2UO2(SO4)2
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Marie (Sklodowska) Curie
Discovery of polonium
and radium
1903 Nobel Prize in Physics
1911 Nobel Prize in Chemistry
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J. J. Thomson
(1856-1940) 英國
1. His experiments suggested not only that cathode rays were
over 1000 times lighter than the hydrogen atom, but also that
their mass was the same whatever type of atom they came from.
2. He concluded that the rays were composed of very light,
negatively charged particles which were a universal building
block of atoms.
3. He determined the charge-to-mass ratio of an electron.
e/m = -1.76 x 108(C/g)
4. The atom must also contain positive particles that balance
exactly the negative charge carried by particles that we now
call electrons.
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Robert Millikan
(1868-1953)
美國
1.
2.
3.
Performed experiments involving
charged oil drops.
Determined the magnitude of the
charge on a single electron.
Calculated the mass of the electron.
e = -1.6 x 10-19 (C)
m = 9.1 x 10-28 (g)
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J. J. Thomson's "plum-pudding" model of the atom
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Ernest Rutherford
1871-1937 英國，紐西蘭
1. Discovered the true nature of the radioactive
radiation, a, b, and g rays. Invented isotope dating.
2. His a particle scattering experiments (1909)
revealed the true nature of the atomic structure.
3. Rutherford became in 1917 the first person to
deliberately transmute one element into another,
when he converted nitrogen into oxygen through the
nuclear reaction 14N + α → 17O + proton.
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拉賽福 a 粒子撞擊實驗 (1910)
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Rutherford’s Gold Foil Experiment
Rutherford’s Gold Foil Experiment
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原子和次原子粒子
• 原子 1-5 Å, Nucleus: 0.00001-0.0001 Å
1Å = 0.00000001 cm
• 構成物質的三種基本粒子:
質子(proton), 中子(neutron), 電子(electron)
• 電荷:
• p = +1, n = 0, e– = –1
• 質量
• p = 1 amu, n = 1 amu, e– = 0.00055 amu
• 6.02×1023 個質子 = 1 公克
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Rutherford’s Model and It’s Problems
Why are atoms stable?
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