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DO NOW:
What is the distance it takes Daniel to go to
the store and go back home? What is his
displacement?
50 meters one way
Masses of Atoms
Essential Question: What is the difference
between the atomic number and the atomic mass?
Is the Atom the Smallest Particle?
• Smaller particles of
matter called quarks
exist but scientist still
consider ATOMS the
basic building blocks
of matter.
• Quark: smaller
particles that make up
protons and neutronssix quarks are known
to exist.
What is Atomic Mass?
• The mass of the atomic particle – also called Mass
Number.
What is the Atomic Number?
• The number of protons in an atom.
• Number of protons also identifies the Element.
How do you find the # of Neutrons for
each element?
• # of Neutrons= Mass Number – Atomic Number
• EX:
# of neutrons= 12.011- 6
6= 12-6
DO Now:
Please Solve:
• 3000mg=_________g???
Find the Neutrons and Protons of:
How do you find the number of Electrons?
• The number of protons is equal to the number
of electrons. We are Assuming that the
element is neutral. This means that the
element does not have a charge.
How does this look when its all
together?
P+=2 (Atomic Number)
N= 4-2=2
e-= 2 (# of protons)
How does this look when its all
together?
P+=2 (Atomic Number)
N= 4-2=2
e-= 2 (# of protons)
Find the p+,n, and e- of each element:
What is a Bohr Model?
• The Bohr model of
the atom
describes the
arrangement of
electrons around
the nucleus of an
atom in terms of
energy levels or
shells around the
nucleus.
• It’s a Picture!
How to draw a Bohr Model?
1. Draw the ______
2. Look on the periodic table to determine the number of e3. Draw the number of electrons on the appropriate shell.
4. First energy level only hold 2 e5. Second energy level only hold 8 e6. Third energy level holds 18 e-
Essential Question: What is the difference
between the atomic number and the atomic
mass?