1. Answer the 3 questions below in your science notebook (write question and answer)
Consider a wooden chair and a balloon. What do these two objects always have in common.
A. Both are made of atoms.
B. Both have the same mass number.
C. Both are made of the same kind of atom.
D. Both are made of the same number of atoms.
An atom’s mass number is 210 and its atomic number is 85. How many neutrons does the atom have?
A. 85
B. 125
C. 210
D. 295
What is the mass number of an atom that has 4 protons, 4 electrons, and 5 neutrons?
A. 4
B. 5
C. 9
D. 13

2. The Building Blocks of Matter: Atoms- - - + + + + - - + + - - -

3. Expectations Benchmark Essential Question
SC.8.P.8.7 Explore the scientific theory of atoms (also known as atomic theory) by recognizing that atoms are the smallest unit of an element and are composed of subatomic particles (electrons surrounding a nucleus containing protons and neutrons).
SC.8.P.8.5 Recognize that there are a finite number of elements and that their atoms combine in a multitude of ways to produce compounds that make up all of the living and nonliving things that we encounter.
Essential Question
How can the number and location of subatomic particles be predicted?
How can I use the periodic table as a tool to understand the number and structure of subatomic particles in an atom?
C – voice level 0
H – raise hand and wait for teacher (do not ask to go to the restroom)
A – guided notes
_M – remain in seat unless given permission
P – independent

4. Matter Anything that has mass and takes up space (volume) Examples:
A brick has mass and takes up space
A desk has mass and takes up space
A pencil has mass and takes up space
Air has mass and takes up space
All of the above examples are considered matter because they have mass and take up space. Can you think of anything that would not be considered matter?

5. Atoms
Smallest possible unit into which matter can be divided, while still maintaining its properties.
Made up of:
protons
neutrons
electrons
The solar system is commonly used as an analogy to describe the structure of an atom - +
For example, what is the
smallest possible unit
into which a long essay can be
divided and still have some meaning? - + + - + + - -

6. Atoms are so small that…
it would take a stack of about 50,000 aluminum atoms to equal the thickness of a sheet of aluminum foil from your kitchen.
if you could enlarge a penny until it was as wide as the US, each of its atoms would be only about 3 cm in diameter – about the size of a ping-pong ball
a human hair is about 1 million carbon atoms wide.
a typical human cell contains roughly 1 trillion atoms.
a speck of dust might contain 3x1012 (3 trillion) atoms.
it would take you around 500 years to count the number of atoms in a grain of salt.
C-C-C-C-C-… + 999,995 more
1 trillion atoms  .
Is made of approximately 3 trillion atoms
Just one of these grains

7. Just how small is an atom??

8. + Protons (+) Positively charged particles
Help make up the nucleus of the atom
Help identify the atom (could be considered an atom’s DNA)
Equal to the atomic number of the atom
Contribute to the atomic mass
Equal to the number of electrons + - +

9. Neutrons Neutral particles; have no electric charge+ -
Neutral particles; have no electric charge
Help make up the nucleus of the atom
Contribute to the atomic mass

10. - Electrons (-) Negatively charged particles
Found outside the nucleus of the atom, in the electron orbits/levels; each orbit/level can hold a maximum number of electrons ( 1st = 2, 2nd = 8, 3rd = 8 or 18, etc…)
Move so rapidly around the nucleus that they create an electron cloud
Equal to the number of protons + - -

11. Hydrogen (H) Atom - Notice the one electron in the first orbital = 1 +
= 0 -
How many
more electrons
can fit in the 1st
orbital/ level? +
Even though there are no neutrons present,
Hydrogen is still considered an atom

12. Oxygen (O) Atom
Notice the two electrons in the first orbital/level and the six in the second + -
= 8
How many
more electrons
can fit in the 2nd
orbital/ level? - - - + + + + - - + + - - -

13. Sodium (Na) Atom
Notice the two electrons in the first orbital/level, eight in the second, and one in the third + -
= 11
= 12 - - -
How many
more electrons
can fit in the 3rd
orbital/ level? - + + + + - - - + + - - - -

14. + The Atom’s “Center” - - -
Protons and neutrons are grouped together to form the “center” or nucleus of an atom.
Notice that the electrons are not apart of the nucleus + - - -

15. What would be the atomic number of this atom?
The number of protons in the nucleus of an atom -
What would be the atomic number of this atom? + - -

16. + Atomic Mass + What would be the mass number of this atom? - - -
The total number of protons and neutrons in an atom’s nucleus
Expressed in Atomic Mass Units (amu)
Each proton or neutron has a mass of 1 amu
What would be the mass number of this atom? - +
 3
 4 + -
3 protons + 4 neutrons = a mass number of 7 amu
Why did we not account for the electrons when calculating the mass number? -

17. Determining the Number of Subatomic Particles:
Atomic Mass
Tells us the
Protons + Neutrons of an atom of that element
Atomic Number
Shows the number of protons
in the nucleus of the atom.
Chemical Symbol
A nickname for the element.
In every atom, the number of protons and electrons are the same.

18. How Many Subatomic Particles?
How many protons can be found in Calcium (Ca)? __________
How many electrons can be found in Calcium (Ca)? __________
How many neutrons can be found in Calcium (Ca)? __________ 20 20 20
# Neutrons = (Rounded) Atomic Mass – Atomic Number

19. https://florida. pbslearningmedia. org/resource/lsps07. sci. phys

20. CYU A. Both are made of atoms. B. Both have the same mass number.
Consider a wooden chair and a balloon. What do these two objects always have in common?
A. Both are made of atoms.
B. Both have the same mass number.
C. Both are made of the same kind of atom.
D. Both are made of the same number of atoms.
A is correct because the matter that makes up both objects is composed of atoms.

21. CYU
An atom’s mass number is 210 and its atomic number is 85. How many neutrons does the atom have?
A. 85
B. 125
C. 210
D. 295
B is correct because the atom’s mass number minus its atomic number is equal to the number of neutrons in the atom. The mass of an electron is too small to be significant.

22. CYU
What is the mass number of an atom that has 4 protons, 4 electrons, and 5 neutrons?
A. 4
B. 5
C. 9
D. 13
C is correct because the mass number is the number of protons, 4, plus the number of neutrons, 5.

23. Horizontal rows are called PERIODS
Periodic table
Mendeleev
The periodic table arranges all the elements in groups according to their similar properties.
FAMILIES/ GROUPS share the same properties! (Columns)
Horizontal rows are called PERIODS
Add a Proton…

24. Example of a Group/Family
Lithium, Sodium, Potassium, etc. share the same properties.
Shiny
Soft
HIGHLY Reactive!

25. Reference your periodic table to help you answer the following question.
Which of the following elements would you expect to have chemical properties similar to Fluorine (F)?
Argon (Ar), because they are both noble gasses.
Beryllium, (Be) because they are in the same period.
Chlorine (Cl), because they are found in the same group.
Neon (Ne), because they have almost the same number of protons.