Changes

===Structure===

===Structure===

Atoms are comprised of three subatomic particles: positively charged [[proton]]s, electrically neutral [[neutron]]s and negatively charged [[electron]]s. 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]]s, electrically neutral [[neutron]]s and negatively charged [[electron]]s. 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. Since protons and neutrons are approximately 2000 times as heavy as electrons, the vast majority of an atom's mass is found in the nucleus. Currently quarks and electrons are considered truly elementary particles, though neither are capable of being seen.

Currently quarks and electrons are considered truly elementary particles, though neither are capable of being seen.

Those who understand electrical theory might notice that positively charged particles packed closely together would repel one another. The nucleus stays together because of what is known as the ''strong nuclear force''. The quantization of this force is a tiny particle called a "gluon".  

Those who understand electrical theory might notice that positively charged particles packed closely together would repel one another. The nucleus stays together because of what is known as the ''strong nuclear force''. The quantization of this force is a tiny particle called a "gluon".