2
edits
Changes
Jump to navigation
Jump to search
Line 1:
Line 1: − + Line 14:
Line 14: + + + +
added a section on isotopes
An '''atom''' is the smallest unit of chemical element that still retains the element's properties. The word atom comes from the Greek term for indivisible, ''átomos''. There have been many ideas about how atoms may look. The current one is called the [[Quantum Mechanical Model]]{{fact}}, and is very complex.{{fact}}
An '''atom''' is the smallest unit of chemical element that still retains the element's properties. The word atom comes from the Greek term for indivisible, ''átomos''. There have been many ideas about how atoms may look. The current one is called the [[Quantum Mechanical Model]]{{fact}}, and is very complex.{{fact}}
==Structure==
===Structure===
Atoms are comprised of three subatomic particles: positively charged [[proton|protons]], electrically neutral [[neutron|neutrons]] and negatively charged [[electron|electrons]]. Protons and neutrons are comprised of quarks and are contained in close proximity in the center of an atom, forming the [[nucleus]]. Electrons inhabit the space around the nucleus, and are arranged around it in a series of layers, known as [[electron shell|shells]] or energy levels.
Atoms are comprised of three subatomic particles: positively charged [[proton|protons]], electrically neutral [[neutron|neutrons]] and negatively charged [[electron|electrons]]. Protons and neutrons are comprised of quarks and are contained in close proximity in the center of an atom, forming the [[nucleus]]. Electrons inhabit the space around the nucleus, and are arranged around it in a series of layers, known as [[electron shell|shells]] or energy levels.
Many common substances are made up of ions. For example, [[sodium chloride]] (NaCl), otherwise known as table salt, is made up of [[sodium cations]] (Na<sup>+</sup>) and [[chlorine]] anions (Cl<sup>-</sup>) in equal proportions. The negatively charged chlorine ions are attracted to the positively charged sodium ions, forming an [[ionic bond]]. This results in a lattice structure, which is responsible for sodium chloride being crystalline in its solid state.
Many common substances are made up of ions. For example, [[sodium chloride]] (NaCl), otherwise known as table salt, is made up of [[sodium cations]] (Na<sup>+</sup>) and [[chlorine]] anions (Cl<sup>-</sup>) in equal proportions. The negatively charged chlorine ions are attracted to the positively charged sodium ions, forming an [[ionic bond]]. This results in a lattice structure, which is responsible for sodium chloride being crystalline in its solid state.
===Isotopes===
Atoms of the same element that have different numbers of neutrons are known as isotopes. Some isotopes are more stable than others, and occur more often in nature, but there is no "standard" number of neutrons in a given element. The atomic weight of an element is a weighted average of the number of neutrons and protons (number of protons remains constant in a given element) in all naturally occurring isotopes.
[[Category:Chemistry]]
[[Category:Chemistry]]
[[Category:Physics]]
[[Category:Physics]]