BIO SCI 93 Lecture Notes - Lecture 2: Covalent Bond, Single Bond, Double Bond
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BIO SCI 93 Full Course Notes
Verified Note
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Document Summary
Matter consists of chemical elements in pure form and in combinations. Matter anything that takes up space and mass. Elements su(cid:271)sta(cid:374)(cid:272)e that (cid:272)a(cid:374)"t (cid:271)e (cid:271)roke(cid:374) dow(cid:374) to a(cid:374)y su(cid:271)sta(cid:374)(cid:272)e (cid:271)y (cid:272)he(cid:373)i(cid:272)al reaction: 92 natural elements, 20-25% are essential elements. Elements substance consisting of two or more different elements combined in a fixed ratio. Essential elements organisms need to live a healthy life and reproduce: oxygen (o), carbon (c), hydrogen (h), nitrogen (n) (1) make up 96% of life matter. Element"s properties depends on the structure of its atoms. Atom smallest unit of matter that retains the properties of an element. Protons and electrons are electrically charged: proton has positive charge, electron has negative charge, neutron neutral. Protons and neutrons are packed together tight in a dense core called atomic nucleus: center of an atom, protons gives the nucleus a positive charge, electron form a negative charge cloud around the nucleus. Mass number(top) sum of protons and neutrons.
