Atom Structure Notes

2. 6 Elements that are needed for
living things ____________
____________ = 96% of the
Human Body

3. Atoms = ________________________
________________________
 = has all the characteristics of
that element
 = ________________________
________________________

4. NUCLEUS
PROTONS positive
(p+)
Neutrons neutral
(n°)
e-
e-
e-
e-
e-
e-
e-
e-
e-
Electron cloud
ELECTRONS
negative (e-)

5. All nuclei are _________ because of the
________.

Each Each elementelement has a different
number of _________

6. NUCLEUS
e-
e-
Energy Levels
e-
e-
e-
e-
e-
e-
e-
e-

7. NUCLEUS
e-
e-
Energy Levels
e-
e-
e-
e-
e-
e-
Example: Oxygen = 8 e-

8. O
Atomic Number
8
15.9994
 The # of p+ in
nucleus
 Determines which
element an atom is
= the total #
of particles
an atom
Atomic Weight

9. O
Atomic Number
8
15.9994
Atomic Weight
then if you
ROUND
You will get the…
Mass Number
= the sum of
p+ and n°
MASS
NUMBER
Number
of p+
Number
of n°
Number of Neutrons =
Mass # - Atomic #

10. O
8
15.9994
So, why is
this a
decimal?
It is an
average of all
the isotopes!
What’s an
isotope?

11. The Nuclei of 3 isotopes of H+
PROTIUM
DEUTERIUM
TRITIUM
1 PROTON
1 PROTON
1 NEUTRON
1 PROTON
2 NEUTRONS
Atoms that have the same # of p+ but different # of n°

12. Example of Compounds:
•Water
•Carbon Dioxide
•NaCl
•C6H12O6
•HCl
•NH4
Substance with atoms of 2
or more elements that are
chemically combined
Compounds =

13. Atoms come together when
the result is more ________
than the individual atoms
NUCLEUS
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
If filled to
capacity then it
is STABLE

14. How do they fill energy levels?
1) BY SHARING ELECTRONS
2) BY GAINING OR LOSING
ELECTRONS

15. Method One: sharing electrons
Example: Hydrogen
e-
e-
e-

16. Examples of Molecules
with Covalent
Bonding: sugars, fats,
proteins, & water

17. MOLECULE = group or atoms held
together by a covalent bond
Examples of Molecules with
Covalent Bonding: sugars, fats,
proteins, & water

18. Method Two:
gaining or losing electrons
An atom (or group of atoms) that gains
or loses electrons = IONION = (charged
particle)
If I lose a negative electron then
I will become more positive
If I gain an electron
then I will become
more negative

19. 11 e-
11 p+
17 e-
17 p+

20. ionic
bond
Ionic bond = attractive force
between 2 ions of opposite charge

21. MIXTURE
Combination of
substances in which
the individual
components retrain
their own properties
Can be separated
Ex: chex mix
SOLUTION
Mixture in which 1 or
more substances
(solutes) are
distributed evenly in
another substance
(solvent)
Ex: Jello