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?

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The Big Question

• How are the different atoms alike and different?

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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

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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