bellwork9.12.2011 1.draw a picture of an atom. label the nucleus, protons, neutrons, and electrons....
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Bellwork9.12.2011
1.Draw a picture of an atom. Label the nucleus, protons, neutrons, and electrons.
2.Give the charges of each of the 3 subatomic particles.
3.Using the periodic table (or your knowledge), list 2 elements and describe their use to us!
Subatomic Particles
Particle Symbol Charge RelativeMass
Electron e- 1- 0
Proton p+ + 1
Neutron n 0 1
Atomic Number
Counts the number of
protons in an atom
Atomic Number on the Periodic Table
11
Na
Atomic Number
Symbol
All atoms of an element have the same number of protons
11
Na
11 protons
Sodium
Learning Check
State the number of protons for atoms of each of the following:
A. Nitrogen (N)
1) 5 protons 2) 7 protons 3) 14 protons
B. Sulfur (S)
1) 32 protons 2) 16 protons 3) 6 protons
C. Barium (Ba)
1) 137 protons 2) 81 protons 3) 56 protons
Mass Number
Counts the number of
protons AND neutrons
in an atom
We can find this, and the atomic number, in something called. . .
Atomic Symbol
Shows the mass number and atomic
number
Na
How to find the # of Neutrons
• The difference between the mass number and the atomic number.
mass number – atomic number = # of Neutrons
How to find the # of Electrons
An atom is neutral So the net charge is zero
Number of protons = Number of electrons
Atomic number = Number of electrons!
Subatomic Particles in Some Atoms
16 31 65 O P Zn
8 15 30
e-
p+
n
Isotopes
Atoms with the same number of
protons, but different numbers of
neutrons. In other words. . . atoms of the same element
(same atomic number) with different mass
numbers
Isotopes of Carbon
Isotopes of Helium
Learning Check
Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C.
12C 13C 14C 6 6 6
#p _______ _______ _______
#n _______ _______ _______
#e _______ _______ _______
Learning Check
An atom of zinc (Zn) has a mass number of 65.
A. Number of protons in the zinc atom
1) 30 2) 35 3) 65
B. Number of neutrons in the zinc atom
1) 30 2) 35 3) 65
C. What is the mass number of a zinc isotope
with 37 neutrons?
1) 37 2) 65 3) 67
Learning Check
Write the atomic symbols for atoms with the following:
A. 8 p+, 8 n, 8 e- ___________
B. 17p+, 20n, 17e- ___________
Atomic Mass on the Periodic Table
11
Na
22.99
Atomic Number
Symbol
Atomic Mass
Atomic Mass
Atomic mass is the weighted average mass of all the isotopes of that atom.
11
Na
22.99
Example of an Average Atomic Mass
Cl-35 is about 75.5 % and Cl-37 about 24.5% of natural chlorine.
Bell Work 9/13/2011
1. What is the atomic number?
2. What is the mass number?
3. Complete the following and give there element names:
14C 44Ca 80Se 6 20 34
#p _______ _______ _______
#n _______ _______ _______
#e _______ _______ _______
The Periodic Table
• An arrangement of elements in which the elements are separated into groups based on properties.
Atomic Number
• The elements are listed by increasing atomic number
ATOMIC # Increases
• Each horizontal row, there are seven
Period
• Each vertical column• Elements that share the same group
have similar chemical and physical properties.
Group
If you didn’t finish these during class do the following for homework:
• p. 111 #15 and 16
• p. 112 #17 and 18
• p. 113 #19 and 20
• p. 116 #21 and 22
• p. 117 #23 and 24
Homework (maybe?)