Vocabulary

Volt or voltage-measurement of electricity in terms of pressure symbol (V) also (E)

Amp or ampere:  Refers to the rate at which electrons flow, one amp is equal to 6.24 x 10 to the 18th electrons moving past a point in one second. (current symbol (I))

Resistance: measured in ohms also referred to as impedance.  It is the resistance to the flow of electrons. symbol (R)

re·sis·tor
rəˈzistər/
noun
PHYSICS

1. a device having a designed resistance to the passage of an electric current.

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VIDEOS

CLASS NOTES

VOLTS:
SYMBOL: (V)
MEASURED IN VOLTS

CURRENT:
SYMBOL: (I)
MEASURED IN AMPERES

RESISTANCE:
SYMBOL: (R) 
MEASURED IN OHMS

POWER/WATTS:
SYMBOL: (W)
MEASURED IN WATTS
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OHM'S LAW
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V=I*R
VOLTS=AMPS X OHMS

POWER

W=V*A

WATTS=VOLTS X AMPS
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The Big Idea: Atoms and Electrons Every atom has: Protons (+) in the nucleus Neutrons (neutral) in the nucleus Electrons (-) moving around the nucleus Electrons exist in different energy levels and regions around the atom. Think of it like: The atom is a building Energy levels are floors Orbitals are rooms Electrons are people filling the rooms
Understanding the Periodic Table The periodic table is arranged by: Atomic number (number of protons) Similar chemical behavior Electron arrangement Rows = Energy Levels The horizontal rows are called periods. Row 1 → first energy level Row 2 → second energy level Row 3 → third energy level
Columns = Similar Electron Patterns Elements in the same column behave similarly because they have similar outer electrons. For example: Lithium (Li) Sodium (Na) Potassium (K) all have 1 electron in their outer shell.

What Does "1s² 2s² 2p⁶ 3s¹" Mean? This is an electron configuration. Each part tells: Energy level number Orbital type Number of electrons there

Breaking It Apart Example: 1s² 2s² 2p⁶ 3s¹
1s² "1" The first energy level "s" The type of orbital "²" There are 2 electrons there So: First energy level s orbital 2 electrons
2s² Second energy level s orbital 2 electrons
2p⁶ Second energy level p orbital 6 electrons
3s¹ Third energy level s orbital 1 electron
Orbital Types Different orbitals hold different numbers of electrons. OrbitalMax Electronss2
p6
d10
f14
Filling Order Electrons fill lower energy orbitals first. The basic order is: 1s
2s
2p
3s
3p
4s
3d
4p
5s ...
Example: Sodium (Na) Sodium has: 11 electrons Its configuration is: 1s² 2s² 2p⁶ 3s¹ Let's count: 1s² → 2 2s² → 2 2p⁶ → 6 3s¹ → 1 Total = 11 electrons That last electron in 3s¹ is why sodium is highly reactive.
How This Connects to the Periodic Table The periodic table blocks match orbital types: BlockOrbitalLeft sides block
Middled block
Right sidep block
Bottomf block So electron configurations literally explain the table’s layout.
A Helpful Analogy Imagine electrons entering a hotel: Floors = energy levels Room types = s, p, d, f Each room has limited capacity Electrons always: Fill lower floors first Spread out before pairing up
Quick Practice Carbon (6 electrons) Configuration: 1s² 2s² 2p² Count them: 2 + 2 + 2 = 6
Oxygen (8 electrons) 1s² 2s² 2p⁴
Magnesium (12 electrons) 1s² 2s² 2p⁶ 3s²
Easy Shortcut You can often predict configurations from the periodic table: Row number = highest energy level Column helps determine outer electrons Block tells orbital type
Why This Matters Electron configurations explain: Why elements react Bonding Electricity Metals vs nonmetals Chemistry behavior Conductivity and materials science They are one of the foundations of chemistry, physics, and engineering.

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