SL atomic structure
SL atomic structure
What are elements?
› Elements are the building blocks of all
› Elements are composed of one type of
What did Dalton say?
› All matter is made of indestructible atoms.
› Atoms cannot be created or destroyed.
› Atoms of the same element are alike.
› Atoms of different elements are different.
› Atoms can be combined together to
What are atoms really like?
› Protons and neutrons in the nucleus.
› Electrons “somewhere” around nucleus.
› Atomic number (proton number) determines
› Neutrons determine isotope.
› Protons + neutrons = mass number.
› Protons – electrons = charge
How do we write a symbol to show
number of p+, n0 and e-?
How do we use isotope concentrations
to find relative atomic mass?
› (mass x %) + (mass x %) . . . = relative atomic mass
› What % of chlorine is Cl-37 and what % is Cl-35 if the
relative atomic mass is 35.5?
What do we use radioisotopes for?
› Carbon-14 radioactive dating.
› Cobalt-60 for radiotherapy of cancer.
› Iodine-131 as a medical tracer.
What information does a mass
spectrometer give us?
› It gives an isotope number and relative
› This information can be used for finding
relative atomic mass.
What is the electromagnetic spectrum?
› This is all wavelengths and frequencies of
What does this have to do with the
hydrogen atom and Bohr?
› Infrared, visible light, and ultraviolet are
absorbed in specific frequencies by the
electrons in a atom as they jump.
The encyclopedia of
What are valence electrons?
› The electrons available in the outer most
energy level are free to bond.
› Most atoms want 8 (or 0) to be stable.
› They will give, take, or share them to be
What is ionization energy?
› This is the energy needed to remove one
mole of electrons from one mole of a
substance in a gas form.
› The more energy, the more “stuck” an
› This will help us further in the next chapter.
What is electron arrangement?
› This is a listing of the numbers of electrons in
each energy level.
› Ca is 2, 8, 8, 2 (highest you need to know for
› What is S?