a positively charged particle in the nucleus
a neutral particle (has no charge) in the nucleus
a negatively charged "particle" outside the nucleus
(actually more of a wave than a particle)
a charged atom or molecule
Examples: Na+, OH-, Al+3
a positively charged atom or molecule
Examples: Na+, NH4+
a negatively charged atom or molecule
Examples: Cl-, SO4-2
one type (weight) of an element
A difference in the number of neutrons
Examples: carbon-12 and carbon-14
a weighted average of the naturally occurring isotopes of an element
the bigger number on the periodic chart, with decimals
# protons + # neutrons = atomic mass
How do you find the number of electrons?
find the atomic number and adjust for the charge
atomic number 9 + 1 extra electron = 10 e-
the number of protons
the smaller number on the periodic chart
a whole number
How do you find the number of protons?
Look at the element's atomic number.
How do you find the number of neutrons?
Subtract the atomic number from the atomic mass.
Shot alpha particles (helium nuclei) at a thin piece of gold foil. Some particles went straight through, others were deflected. Demonstrated that atoms are mostly empty space with a dense core (nucleus). Disproved the plum pudding model.
He electrified hydrogen gas until it glowed then separated the light with a prism. Demonstrated that there are particular wavelengths of light being given off, which is characteristic of the element. The atomic spectrum shows how much energy is released by the excited electrons falling back down to the ground state.
Which atom has the larger atomic radius, Ca or Ca+2?
They have the same number of protons. Ca has two more electrons, which makes its electron cloud larger.
Which atom has the larger atomic radius, F- or Na+?
F- They have the same number of electrons (10).
F has 9 protons and Na has 11. More protons pull in the electron cloud more, which makes Na+ the smaller atom.
A radioactive atom breaks apart into two atoms, a helium nucleus (2 protons and 2 neutrons) and the left overs.
A radioactive atom breaks apart into an atom and an electron. One of the neutrons splits into a proton and an electron.
4 sources of the elements
1-4 Big Bang
5-26 stellar fusion (the star's life)
27-92 super nova (star death)
93+ man made
react with water
alkali earth metals
not as reactive as alkali metals
middle of the periodic chart
very stable (gold, silver, copper)
bright colors (sapphire, ruby, emerald, paint, etc)
can be +1, +2, or +3 charges
good conductors of heat and electricity
malleable and ductile
gasses or brittle solids
tend to form acids
diatomic (F2, Cl2, Br2, I2)
completely stable; don't react with anything
full s and p orbitals
the row number
the electrons in the outer energy level
same number as the column number
shown as dots around the symbol in a Lewis Dot Diagram
A list of where the electrons reside in the electron cloud. Can be abbreviated using the nearest noble gas.
the 4 variables which define an orbital: n, l, ml, ms
The numbers are inserted into equations and graphed. The 3D graph shows the space where the electron is most likely to be found (the orbital).
the region of space where an electron is likely to be found
Each orbital can hold two electrons (of opposite spin)
there is a single s orbital at every energy level
there are 3 p orbitals at every energy level except the first level
various shapes, including clover leaf
there are 5 d orbitals in the 3rd energy level and at all the higher energy levels
4th energy level and above
there are 7 different f orbitals
s block elements
Alkali metals and Alkali Earth metals
p block elements
includes all the nonmetals
d block elements
the transition metals
because of the d orbitals, these elements have more than one stable charge
Ex: Fe+2 and Fe+3
f block elements
lanthanides and actinides (bottom two rows of periodic chart)