3.2 - Atomic Structure Flashcards
atom
smallest particle of an element that contains electrons surrounding a nucleus that contains protons and neutrons
molecule
a group of two or more atoms chemically combined which retains the properties and composition of the substance
proton relative mass and charge
Relative Mass Charge
1 +1
neutron relative mass and charge
Relative Mass Charge
1 0 (neutral)
electron relative mass and charge
Relative Mass Charge
1/1840 -1
atomic number
number of protons in the nucleus of an atom
mass number
number of protons and neutrons in the nucleus of an atom
isotope
atoms of the same element which have the same number of protons but a different number of neutrons
calculating relative atomic mass
(% isotope A x mass isotope A) + (% isotope B x mass isotope B)
_____________________________________
100
row on periodic table shows
period
- these are the horizontal rows that show the number of shells of electrons
column on periodic table shows
group
- these are the vertical columns that show how many outer electrons each atom
the further away the electron from the nucleus
the more energy a shell has
shell configuration
2,8,8
number of shells in shell configuration shows
period of the element
last shell number in shell configuration shows
group of the element
metals and non-metals on periodic table
- metals are on the left
- non-metals on the right
where are noble gases on periodic table
right column, group 0
why are noble gases unreactive
- group 0
- most elements participate in reactions to complete their outer shells by losing, gaining, or sharing electrons
- group 0 elements do not do this because they have full outer shells of electrons
- they are therefore unreactive (inert) and do not form molecules easily
