ch1- atomic structure Flashcards
whatre the 3 states of matter
liquids solid and gas
describe movement and arangement of particles in gas molecules
-easily compressed
-particles are widely spaced
-have no fixed volume so theyt take shape of container
-move rapidly and quickly
describe movement and arrangement of particles in liquid molecules
-closely packed little spaces
-can flow
-no fixed volume so they take shape of their container
-flow
describe movement and arangement of particles in solid molecules
-fixed shape and volume
-particles packed closesly in a fixed pattern
-vibrate which generates kinetic energy
-cant be compressed
whatre the 2 changes of states that involve particles coming closer together and where do they transfer energy
-condensation (gas to liquid)
-freezing (liquid to solid)
they transfer energy to their surroundings since theyre reforming bonds between particles (exothermic)
whatre the 2 changes of states that involve particles seperating and where do they transfer energy
-melting (solid->liquid)
-evaporation (liquid->gas)
they take in energy from surrounding (endothermic)
whatre the 2 factors that effect diffusion
- state of matter (diffusion takes place faster in gasses than liquids)
-density of particles (small and light particles diffuse faster than heavy larger ones)
stronger forces between particles=…
more energy required to break up the intermolecular forces
define and give an example of a molecule
2 or more atoms held by chemical bonds ex-oxygen or water
define a compound
2 or more different elements held together by chemical bonds
define and give an example of mixture
-2 or more substances that are physically but not chemically bonded
ex- air, since it has oxygen carbon dioxide and nitrogen
state the relative mass of each subatomic particle
proton-1
neutron-1
electron- very small (0)
state the relative charges of each subatomic particle
proton +1
electron -1
neutron- 0
whats the atomic number
number of electrons=protons in an element
what does the mass number constist of
proton+neutron
what do groups share
similar chemical properties due to same amount of electrons on outer shell
what 4 scientists were involved in the nuclear model
- jj thompson
-niels bohr
-ernest rutherford
-james chadwick
describe the plum pudding model
-jj said that the atom was a dense sphere with equally distributed mass. electrons embedded into the sphere
how was the nuclear (nucleus) model disovered
alpha particle scattering experiment
-ernest found that atoms were mainy empty space with a dense and positively charged nucleaus that orbits electrons
what did niels bohr dicover
that electrins orbit the nucleaus at specific energy levels
what did chadwick discover
that a the nucleas also contained neutrons
define an isotope
an atom with the same number of proton but different neutrons
whats relative atomic mass
the average mass of an isotope
whatre ions
atoms with an overall charge due to loosing or gaining an electron
why do atoms have no overall charge
cause proton = electron so the charges cancel eachother out
whats the max number of electrons held in the 1st,2nd,and 3rd shell
2,8,8
why do elements in the same group have similar chemical properties
because they all have the same amount of electrons on their outter energy shells
