1. Atoms, Elements &
Compounds

2. Atoms, Elements, and
Compounds
Atom
1)_____ : basic unit
of matter
a) Anything that
occupies space
and has
______.
mass

3. Atoms, Elements, and
Compounds
b. Composed of:
protons (+),
neutrons ( 0 ),
electrons ( - )

4. Atoms, Elements, and
Compounds
c) Protons and neutrons are found in
nucleus
the ______ of the atom
i. The number of protons (and electrons)
in an atom is determined by the
atomic
________ number.
ii. The number of neutrons is determined
by subtracting the ___________ from
Atomic number
the ___________.
Atomic mass

5. Atoms, Elements, and
Compounds
#protons = 6
# neutrons = 12- 6 = 6
# electrons = 6

6. Atoms, Elements, and
Compounds
d) orbit
Electrons _________ around the
nucleus in energy levels, or
____________
shells
i. These shells represent the most
probable place that an electron can
be found at any one time.
ii. Each shell holds a different
number
_________ of electrons.

7. Bohr Models
p 2 8 8*
n
The * orbital actually holds more
than what is listed. You will learn
more about this if you take
Chemistry!

8. Atoms, Elements, and
Compounds
iv. To properly place an atom’s electrons
in the orbitals, follow these guidelines:
1) Start with the innermost shell and
draw two electrons
2) If you have electrons left, move to
the next shell and draw up to eight
electrons; continue filling up shells
until you run out of electrons.

9. Bohr Models
Sodium
11 p 2 8 8*
12 n

10. Atoms, Elements, and
Compounds
v.The electrons in the outermost shell
valence
Carbon Iodine

11. What is the valence # of Oxygen?

12. Atoms, Elements, and
Compounds
2)Element: pure substance made of
one
______ type of atom
i. Grain of Sand (Atom) vs. Beach (Element)
ii. Periodic Table of Elements
iii. Six most important elements for living things:
C,H,O,N,P,S

13. Atoms, Elements, and
Compounds
3) Isotope: ______ element,
same
different number of ________.
neutrons

14. Atoms, Elements, and
Compounds
a) Ex: C-12, C-13, C-14

15. Atoms, Elements, and
Compounds
b) Same chemical
properties
_____________ due
to same number of
protons
_____________.

16. Atoms, Elements, and
Compounds
4) Compound: Two or more
definite
elements in ________
proportions.
a) formula
Has a chemical ________.
ex. H2O, NaCl, C6H12O6
b) Compounds are different than the
elements that make them up

17. Atoms, Elements, and
Compounds
i. Ex: Sodium (Na) explodes in
cold water, chlorine (Cl) is a
poisonous gas. NaCl is ______.
salt
+ =

18. Atoms, Elements, and
Compounds
ii. Oxygen (O2) and Hydrogen (H2)
individually are gases, but together
they are a liquid (H2O)!!
+ =