topic 1 - atomic structure and the periodic table Flashcards
atomic structure
has a nucleus. in the nucleus are protons and neutrons. electrons orbit.
details on subatomic particles
proton has a relative mass of 1 and a charge of +1. neutron has a mass of 1 and a charge of 0. election has a mass of close to 0 and a charge of -1
what do atomic number and mass number tell u
atomic number is the no. of protons
mass number is the no. of protons + neutrons
elements
consist of atoms with the same atomic number
compounds
a compound is a mixture which is chemically bonded
mixture
a mixture is two or more elements mixed together. not chemically bonded
isotopes
different forms of the same element with a slightly different amount of neutrons.
history of atom
start 19th century - john dalton, solids spheres
1897 - jj thompson, said atoms had electrons and made plum pudding model
1909 - ernest rutherford, alpha particle scattering experiment. nuclear model
james chadwick provides evidence for nuetrons
development of the periodic table
mendeleev. dude came and put the elements based on atomic weight and left gaps within the table.
metals
strong, very malleable
great at conducting heat and electricity
high boiling and melting points
non-metals
dull looking, brittle, arent always solid at room temp, generally don’t conduct electricity and often have a lower density compared to metals
group 1 elements
alkali metals
lithium
sodium
potassium
etc
trends when going down:
increasing reactivity
lower melting and boiling points
group 7 elements
halogens
fluorine chlorine bromine iodine etc
trends u are going down the list:
less reactive
higher melting and boiling points
group 0 elements
noble gases
helium
neon
argon
boiling point increases the lower u go
they aren’t very reactive and are therefore non-flammable
