Fast heart rate: Tachycardia means fast heart beat. Sinus node is the structure where normally heart rhythm and beat is originated, and it naturally responds to stimuli when the heart needs to beat faster. Inappropriate sinus tachycardia is when the heart is beating fast, when it shouldn't. ...Read more.
An atom is the smallest unit of an element that retains the identity (and the chemical properties) of that element. + 66 others found this useful. Sandra Pinzon.Edit.he atom is the smallest particle of an element that retains it's characteristics. Sub-atomic particles such as protons, neutrons and electrons form the atom and it is the amo â¦ unt of each of these sub-atomic particles that make the element that element. 5 people found this useful.
From Wikipedia, the free encyclopedia. Chemical composition refers to the arrangement, type and ratio of atoms in molecules of chemical substances. Chemical composition varies when chemicals are added or subtracted from a substance, when the ratio of substances changes, or when other chemical changes occur in chemicals.The chemical composition of a substance determines the properties of the substance.This means that the way atoms are put together in something determines the color, density, strength, and other properties of the thing. This short article about chemistry can be made longer. You can help Wikipedia by adding to it.he chemical composition of a substance determines the properties of the substance. This means that the way atoms are put together in something determines the color, density, strength, and other properties of the thing. This short article about chemistry can be made longer. You can help Wikipedia by adding to it.