The Chemical Basis of Life Flashcards
occupies space and has mass
matter
amount of matter in an object
mass
gravitational force acting on an object
weight
international unit for mass
kilogram (kg)
simplest type of matter having unique chemical properties
element
smallest particle of an element that has the chemical characteristics of that element
atom
no electric charge
neutron
one positive charge
proton
one negative charge
electron
where are protons and neutrons found
nucleus
protons and neutrons are found in the center of the atom called
nucleus
electrons are found in …
electron cloud
number of protons in each atom
atomic number
two or more forms of the same element have the same number of protons and electrons but different number of electron
isotopes
sharing or transferring their outermost electrons forms ….
chemical bonds
energy levels are often drawn as concentric rings called
electron shells
outermost shell
valence shell
combining with other atoms until each has 8 electrons
octet rule
atoms achieve octet in one of two ways:
- transferring electrons between atoms
- sharing electrons between atoms
ability of the atom’s nucleus to pull electrons toward it
electronegativity
a charged particle
ion
forms when electrons transferred between atoms, creating oppositely charged ions
ionic
forms when atoms share one or more pairs of electrons
covalent bond
Forms when two hydrogen atoms are held together by a nonpolar covalent bond
nonpolar molecule
forms when electrons are shared equally between the nuclei
nonpolar covalent bond
forms when atoms involved in a covalent bond have different electronegativities
polar covalent bonds
polar covalent bonds can result in …. which are electrically asymmetric
polar molecules
substance resulting from the chemical combination of two or more different types of atoms
compound
weak charge attractions that exist between separate molecules, or between ions and molecules
intermolecular forces
forms when positively charged hydrogen is attracted to the negatively charged O, N or F of another molecule
hydrogen bond
complete transfer of electrons between two atoms results in separate positively charged and negatively charged ions
ionic bond
example of ionic bond
NaCl, sodium chloride
unequal sharing of electrons between two atoms……
polar covalent bond
equal sharing of electrons between two atoms
nonpolar covalent bond
attraction of oppositely charge ends of one polar molecule to another polar molecule holds molecules or parts of molecules together
hydrogen bond
dissociated ions are called
electrolytes
when ionic compounds dissolve in water, their ions …., or separate from each other
dissociate
formation or breaking of chemical bonds between atoms, ions, molecules, or compounds
chemical reactions
substance that enter into a chemical reaction is called
reactants
substance that result from the chemical reaction
products
when two or more reactants combine to form a larger, more complex product
synthesis reaction
synthesis reaction is represented symbolically as
A+B —-> AB
synthesis reactions that occur in the body
anabolism
synthesis reactions in which water is also a product
dehydration reactions
reactants are broken down into smaller, less complex products
decomposition reaction
decomposition reaction is represented as
AB —-> A+B
decomposition reactions that occur in our body
catabolism
reactions that use water in breaking down food
hydrolysis reactions
all of anabolic and catabolic reactions in the body are collectively defined as
metabolism
combination of a decomposition reaction and a synthesis reaction
exchange reaction
exchange reaction is symbolically represented as
AB + CD —-> AC + BD
reaction can run in the opposite direction, so that the product are converted back to the original reactants
reversible reaction
when product formation is equal to the rate of reactant formation
equilibrium
