the chemistry of life Flashcards
what is matter?
the universe consists of matter which is moved around by energy.
matter occupies space and has a mass.
composed of elements
what are the 3 states of matter?
solid-definite shape and volume
liquid-definite volume , flows to fill space
gas-no defined shape or volume
what is energy?
energy is the ability to put matter into motion
capacity to do work
what is the difference between kinetic and potential energy?
kinetic - is that which moves things
potential- stored energy.when the energy is released it becomes kinetic energy.
what are some forms of energy?
chemical energy- stored in chemical bonds- ATP
electrical energy-movement of charged particles- nervous system
mechanical energy- energy directly involved in moving matter
radiant energy-energy that travels in waves
what are elements made of?
composed of atom.
what is the size of the smallest element?
smaller than 0.1nm
what is the size of largest element?
0.5nm
what are the 4 elements that make up 96.1% of our body?
C , O , H , N
how do elements differ from each other?
elements differ from each other by the number of protons, neutrons and electrons.
what is an isotope?
same number of electrons and protons but different number of neutrons.
each element has at least 2 isotopes.
what are molecules of an element?
when atoms of same element combine
e.g. H2 S8
what are molecules of a compound?
different kind of atoms combine.
e.g. H20
what are mixtures?
2+ components physically intermixed
what are the three types of mixture?
- solution
- colloids
- suspensions
what is the difference between compound and mixture?
.no chemical bond in mixture
.mixture can be separated physically via evaporation or filtering or straining
.compounds need chemical binds to be broken to separate
.compound is always homogenous
.mixture can be heterogenous or homogenous.
what are the three types of chemical bonds? and what do they do?
.ionic
.covalent
.hydrogen
they make sure that the atom is stable with 8 electrons in its valence shell
what does each electron shell represent?
each electron shell represents different energy level.
electrons therefore have potential energy
electron further away from nucleus has most potential energy.
what is ionic bonding?
two oppositely charged ions attract.
intermediate strength