Unit 1: Chemistry Of Life Flashcards
Substance that can not be broken down into other substances by chemical reactions
Elements
There are about how many naturally occurring chemical elements?
100
About how many elements are essential for living organisms
25
4 most important and abundant elements
CHON: Carbon, hydrogen, nitrogen, oxygen
CHON
Carbon, hydrogen, oxygen, nitrogen
Smallest unit of matter that still retains properties of an element
Atom
Positively charged particles in the nucleus of an atom
Protons
Neutral particles in the nucleus of an atom
Neutron
Negatively charged particles surrounding the nucleus in layers
Electron
Atomic number
Number of protons
of protons = # of electrons
True
Number of protons + average number of neutrons in an atom
Atomic mass
Atoms of the same element differing in number of neutrons
Isotopes
Atom that has lost or gained electrons, becoming charged
Ion
Bond between oppositely charged ions, where electron transferred from one atom to the other
Ionic
Bond between atoms sharing electrons
Covalent
Attraction of an atom in a bond for electrons
Electronegativity
Equal sharing of electrons in a covalent bond
Nonpolar covalent bond
Unequal sharing of electrons in a covalent bond where one atom has a higher electronegativity than the other atom
Polar covalent bond
Weak, intermolecular bond between a hydrogen atom in one molecule and an electronegative atom in another molecule
Hydrogen bond
Molecule with opposite ends being oppositely charged
Polar molecule
In H2O, oxygen is partially __ and hydrogens are partially __.
Negative, positive
Water molecules sticking together, results in water being liquid
Cohesion
Water molecules sticking to other polar substances
Adhesion
Difficulty breaking the surface of a liquid
Surface tension
Takes extra heat to break hydrogen bonds so water can evaporate
High specific heat
Water is less ___ as a solid
Dense
Water is capable of dissolving ionic compounds and many molecules. Water is a
Universal solvent
Form determines
Function
Dissolving agent
Solvent