This document discusses how the structures of atoms differ. It provides information on the number of protons, electrons, and neutrons that various elements contain. It also defines key atomic concepts like isotopes, valence electrons, and how ions are formed through the gaining or losing of electrons. Tables are included that list elemental properties and isotopic information.

1. HOW DO STRUCTURES OF
ATOMS DIFFER?

2. Li Mg Cu Br He S Na K Fe
Lithium Magnesium Copper Bromine Helium Sulfur Sodium Potassium Iron
Mass Mass Mass Mass Mass Mass Mass Mass Mass
#7 #24 #64 #80 #4 #32 #23 #39 #56
Atomic Atomic Atomic Atomic Atomic Atomic Atomic Atomic Atomic
#3 #12 #29 #35 #2 #16 #11 #19 #26
Protons: Protons: Protons: Protons: Protons: Protons: Protons: Protons: Protons:
3 12 29 35 2 16 11 19 26
Electrons: Electrons: Electrons: Electrons: Electrons: Electrons: Electrons: Electrons: Electrons:
3 12 29 35 2 16 11 19 26
Neutrons: Neutrons: Neutrons: Neutrons: Neutrons: Neutrons: Neutrons: Neutrons: Neutrons:
4 12 35 45 2 16 12 20 30
ELEMENTAL CHART

3. Li Mg Cu Br He S Na K Fe
Lithium Magnesium Copper Bromine Helium Sulfur Sodium Potassium Iron
1e 2e 2e 7e 2e 6e 1e 1e 2e
VALENCE ELECTRONS
...are electrons in the last shell or energy level of an atom.

4. Li Mg Cu Br He S Na K Fe
Lithium Magnesium Copper Bromine Helium Sulfur Sodium Potassium Iron
Li-8 Mg-25 Cu-65 Br-81 He-5 S-33 Na-24 K-40 Fe-57
ISOTOPES
...are atoms that contain the same number of protons but a
different number of neutrons which makes isotopes differ.

5. Carbon-14 Nitrogen-15 Sulfur-35 Calcium-45
8 8 17 25
ISOTOPES (CONT.)
Subtract number of protons from number of isotopes to find
the number of neutrons

6. When atoms gain or lose electrons, they become electrically charged.
• Gain - More electrons than protons; net negative charge
•Lose - More protons than electrons; net positive charge
A fluorine atom accepts an electron to form an ion with a single negative charge.
FORMING IONS