what are atoms
smallest particle that can have chemical characteristic of element
what is inside an atom
sub-atomic particles
what are the sub-atomic particles inside an atom
- protons
- neutrons
- electrons
features of protons
- found in nucleus
- relative charge: +
- relative mass: 1
features of neutrons
- found in nucleus
- relative charge: 0
- relative mass: 1
features of electrons
- found in electron shell
- relative charge: -1
- relative mass: 1/1840
what can you find from the periodic table
- number of protons
- number of protons + neutrons
- number of electrons (proton = electrons)
another way of saying number of protons
- atomic number
- proton number
another way of saying number of protons and neutrons
- mass number
- atomic mass
- nucleon number
why is the mass number in the periodic table a decimal
it is an average of the various isotopes of an element
what is an isotopes
atoms of the same element with the same number of protons but different number of neutrons (mass number is different)
what happens when there is different number of neutrons
- mass change
- density change
- different physical properties
what is neuclide notation
where the mass number and proton number is placed beside a atomic symbol
what is the most number of electrons in each shell
(1st shell, 2nd shell, etc.)
- 2
- 8
- 8
- 32
what is the outer most electron shell called
valence shell
what is the outer most electron called
valence electron
features of the valence shell
furthest away from the nucleus, possess greatest energy
features of noble gas
- stable
- unreactive (inert)
- full valence electron shell
what are ions
atoms that gain/lose electrons
purpose of ions
obtain full electronic configuration
what are cations
positively charged ions
what are anions
negatively charged ions
what are the elements called in group 3-12
transition elements
what is the charge of ions in group 1
+
(positive)
