the chemical level of organization Flashcards
(45 cards)
what are the 3 basic principles of chemistry
- chemistry is the science of structure and interactions of matter
- matter is anything that has a mass and takes up space
- mass is the amount of matter a substance contains, whereas weight is the force of gravity acting on mass
chemical element
matter exists in 3 forms:
solid
liquid
gas
all forms of matter and composed of chemical elements
elements
elements are given chemical symbols such as :
o=oxygen
c=carbon
h=hydrogen
n=nitrogen
these elements make up the majority of our bodies
what are the main chemical elements in the body
oxygen ; o
carbon ; c
hydrogen ; h
nitrogen ; n
the percentage is about 96% of total
what are the lesser element in our body and the percentage
calcium ; ca
phosphorus ; p
potassium ; k
sulfur ; s
sodium ; na
chlorine ; cl
magnesium ; mg
iron ; fe
the percentage is about 3.6% of total
what is the trace element percentage
the percentage is about 0.4% of total
what are atoms
chemical elements are composed of units of matter of the same type called atoms
atoms are the smallest units of matter that retain the properties and characteristics of an element
what is an atomic number and mass number
atomic number is the number of protons in the nucleus of an atom
mass number is the number of protons and neutrons in an atom
what is an atomic mass
atomic mass assumes the mass of the neutron, proton, and electron
the atomic mass\weight of an element is the average mass of all its naturally occurring isotopes
what is an ions, molecules, and compounds
ion is an atom that has lost or gained an electron
molecule as 2 or more atoms sharing electrons
compounds is a substance that can be broken down into 2 or more different elements
what is a chemical bond
a chemical bond occurs when the atoms are held together by forces of attraction
the number of electrons in the valence shell determines the likelihood that an atom will form a chemical bond with another atom
what is a cations ions
a positive charge ion
when you give an electron
what is an anions ion
is a negative charge ion
when you receive an electron
covalent bonds
can be single, double, and triple bonds
what is an hydrogen bond
hydrogen bonds result from the attraction of the oppositely charged parts of molecules
hydrogen bond and water
hydrogen bonds between water and molecules give water cohesion
cohesion is the tendency of like particles to stay together
hydrogen bonds create surface tension
surface tension is a measure of the difficulty of stretching or breaking the surface of a liquid
what is a chemical reactions
chemical reactions occur when new bonds are formed or old bonds are broken
reactants are the starting substances
products are the ending substances
metabolism
forms of energy and chemical reactions
energy is the capacity to do work
potential energy
kinetic energy
chemical energy
law of the conservation of energy- energy can neither be created nor destroyed but it can be converted from one form to another
energy transfer
exergonic reactions
endergonic reactions
activation energy
the type of chemical reactions
synthesis
decomposition
exchange
reversible
oxidation-ruduction
oxidation-reduction reactions
these reactions transfer electrons between atoms and molecules and always occur in parallel(when one substance is oxidized is reduced)
oxidation is a loss of electrons and energy release
reduction is the gain of an electrons and energy gain
inorganic vs organic compounds
inorganic compounds usually lack carbon and are simple molecules
water is the most important and abundant inorganic compound in all living things
organic compounds always contain C, usually contain O, and always have covalent bonds
water in a chemical reactions
water is the ideal medium
in a hydrolysis reaction, water is added to break bonds
in a dehydration synthesis reaction, water is removed to make bonds
what re the thermal properties of water
water has a high heat capacity and a high heat of vaporization
