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.
All elements and the chemical reactions between them obey the same chemical and physical laws, regardless of whether they are a part of the living or nonliving world. The structure of the atom An atom is the smallest unit of matter that retains all of the chemical properties of an element.