Alchemy Unit – Investigation II
Protons, Neutrons, Electrons, And Mass
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© 2004 Key Curriculum Press.
Admit Slip
• What is calcium’s symbol?
• What is the atomic number of calcium? • What is the number of protons? • What is the atomic mass of calcium?
© 2004 Key Curriculum Press.
The Big Question
• How are the different atoms alike and different?
© 2004 Key Curriculum Press.
Today’s Objectives
Students will be able to: • Explain how the periodic table of
elements is organized.• Use the periodic table to find the atomic
mass, atomic number, number of protons, electrons, and neutrons
© 2004 Key Curriculum Press.
Agenda• Admit Slip• Periodic Table Review• Notes• Exit Slip• Homework
© 2004 Key Curriculum Press.
Name
Atomic Mass
Symbol
Atomic Number
© 2004 Key Curriculum Press.
Atomic number = # of protons
# of protons = # of electrons Positive(+) charge = Negative(-) charge.
This is why atoms are neutral, with a 0 charge overall!
Protons, Neutrons, and Electrons 9/18/13
© 2004 Key Curriculum Press.
• Mass number is the number of protons plus the number of neutrons for each element.
• It is equal to the atomic mass rounded to the nearest whole number.•mass number = protons + neutrons•mass number atomic mass
© 2004 Key Curriculum Press.
• If mass number = protons + neutrons, how do you find the neutrons from the mass and protons?
• To find the number of neutrons, you round off the atomic mass to a whole number and then subtract the protons.
Neutrons = mass number – protons.
© 2004 Key Curriculum Press.
Classwork/Exit Slip
Element Symbol Atomic #
# of protons
# of electrons
# of neutrons
Mass number
Atomic Mass
tungsten 184 183.8529 35
gold 118
© 2004 Key Curriculum Press.
Classwork/Exit Slip
© 2004 Key Curriculum Press.
Homework# 1 – 5 Due tomorrow
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