(Encyclopedia) Rydberg, Johannes RobertRydberg, Johannes Roberty&oomacr;ˈhänəs rôˈbərt rüdˈbĕryə [key], 1854–1919, Swedish physicist. Rydberg was a professor at Lund from 1901 to 1919. He is best…
(Encyclopedia) Hevesy, Georg vonHevesy, Georg vongāˈôrkh fən hĕˈvĕshē [key], 1885–1966, Hungarian physicist and chemist. He received the 1943 Nobel Prize in Chemistry for his work on the use of…
(Encyclopedia) atomic number, often represented by the symbol Z, the number of protons in the nucleus of an atom, as well as the number of electrons in the neutral atom. Atoms with the same atomic…
(Encyclopedia)
Elementary Particles
Leptons
Particle
Symbol
Mass (MeV/c2)
Electric Charge
electron
e−
0.511
−1
muon
μ-
105.7
−1
tau
τ
1784.1
−1
electron neutrino
νe
<7.3×10−6
0
muon…
(Encyclopedia) Geologic Timescale
Era
Period
Epoch
Approximate duration
(millions of years)
Approximate number of years ago
(millions of years)
Cenozoic
Quaternary
Holocene
10,000 years ago to…
(Encyclopedia)
Morse Code
International Morse Code
Letters
A
· –
B
– · · ·
C
– · – ·
D
– · ·
E
·
F
· · – ·
G
– – ·
H
· · · ·
I
· ·
J
· – – –
K
– · –
L
· – · ·
M
– –
N
– ·
O…
(Encyclopedia) Nobel Prizes
Year
Peace
Chemistry
Physics
Physiology or Medicine
Literature
1901
J. H. Dunant
Frédéric Passy
J. H. van't Hoff
W. C. Roentgen
E. A. von Behring
R. F. A. Sully-…
(Encyclopedia) Trigonometric Functions
Function (abbreviation)
Definition
Formula
sine (sin)
opposite / hypotenuse
sin A = a&fbar;c
cosine (cos)
adjacent / hypotenuse
cos A = b&fbar;c…
