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Frequently Asked Questions in Cosmology
Electron
The electron (symbol: e − ) is a subatomic particle with a negative elementary electric charge . [ 8 ] An electron has no known components or substructure. It is generally thought to be an elementary particle . [ 2 ] An electron has a mass that is approximately 1/1836 that of the proton . [ 9 ] The intrinsic angular momentum ( spin ) of the electron is a half-integer value in units of ħ , which means that it is a fermion .
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number , which is the number of protons in its nucleus . Elements are divided into metals , metalloids , and non-metals . Familiar examples of elements include carbon , oxygen ( non-metals ), silicon , arsenic ( metalloids ), aluminium , iron , copper , gold , mercury , and lead ( metals ).
Ununoctium is the temporary IUPAC name [ 11 ] for the transactinide element having the atomic number 118 and temporary element symbol Uuo .
Ununoctium
Electromagnetic radiation
The electromagnetic waves that compose electromagnetic radiation can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. This diagram shows a plane linearly polarized EMR wave propagating from left to right. The electric field is in a vertical plane and the magnetic field in a horizontal plane.
Illustration of the relative abilities of three different types of ionizing radiation to penetrate solid matter. Alpha particles (α) are stopped by a sheet of paper while beta particles (β) are stopped by an aluminium plate.