Download Atomic Numbers Notes

WARM UP
“Learn to enjoy the little things – there are so
many of them.”
1. What does this quote mean to you?
2. How can you practice this in your everyday
life?
3. How does this apply to Chemistry?
Atomic Numbers
Atomic Number
• Number of protons (p+)
– Determines identity of atom/element
# of Electrons
• Electrons (e-) in an atom
– # of p+ = # of e-
Mass Number
• # of p+ + # of neutrons (n0)
Atomic Symbols
• Carbon: 6 p+, 8 n0, 6 e-
Carbon-14
Isotopes
• Atoms with a different number of n0
– Same atom/element, different mass
• Radioactivity if too many n0
– Too many particles, some “thrown out”
WRAP UP
Protons
Neutrons Electrons Atomic
Number
Neon
10
Titanium
22
Uranium
92
Mass
Number
20
26
238
ANSWERS
Protons
Neutrons Electrons Atomic
Number
Mass
Number
Neon
10
10
10
10
20
Titanium
22
26
22
22
48
Uranium
92
146
92
92
238
WARM UP
• If an atom has 19 p, how many e
does it have?
• If an atom has 11 p, 11 e, and 19
n, what is its mass?
• How many p does an atom with
36 n and 29 e have?
WRAP UP
• Draw a model of an atom with 4 protons, 3
neutrons, and the correct number of
electrons.