Tobin Science — Periodic Table Patterns
Where an element sits tells you what it does. Rows, columns, charges, ions.
Two numbers tell you almost everything
The periodic table is not a list. It is a seating chart. Find the row and the column, and you already know how many shells the atom has, how many valence electrons it has, and what charge it will take when it becomes an ion.
↘ The ROW is the PERIOD
The period number tells you how many electron shells the atom has. Period 3 means three shells. Every element in that row has three shells, no exceptions.
Period number = number of electron shells
Period 1 → 1 shellPeriod 2 → 2 shellsPeriod 3 → 3 shells
↓ The COLUMN is the GROUP
For the main groups, the group number tells you how many valence electrons are in that outer shell. Groups 1 and 2 give you 1 and 2. Groups 13–18 give you the group number minus 10.
Group 1–2 → valence = group number
Group 13–18 → valence = group number − 10
Group 13–18 → valence = group number − 10
Group 2 → 2 valenceGroup 16 → 6 valenceGroup 17 → 7 valence
The catch: the transition metals in the middle (groups 3–12) do not follow the valence rule. Their outer shells fill in a messier order, which is exactly why their charges vary and why you get told the charge instead of predicting it.
Color the table by…
Click a color to see the pattern. Click any element for its full card. Click a legend chip to spotlight just that group.
Oxidation numbers across the table
The oxidation number is the charge an atom takes when it becomes an ion. Read it left to right: metals on the left hand electrons away and go positive, nonmetals on the right take electrons in and go negative, and the far right column does neither.
Group 14 sits on the fence. Carbon and silicon have four valence electrons — exactly half. Losing four or gaining four are equally hard, so instead of forming ions they usually share electrons. That sharing is what covalent bonding is, and it is why carbon can build millions of different molecules.
Every family, one card each
Ten families. Learn the column and you have learned every element in it.
The mix-ups that cost the most points
Watch the charge happen
An atom starts neutral: the protons and the electrons cancel out. Nothing about the nucleus ever changes — protons stay put. Only electrons move. Pick an element and press play.
Element:
protons (+)
electrons (−)
valence electrons
Speed
Two atoms, one transfer
Electrons do not vanish. When a metal loses them, a nonmetal is standing right there to take them. Watch a full handoff — one atom goes positive at the exact moment the other goes negative, and the opposite charges snap together.
Pick a pair above.
The rule underneath all of it
− Lose electrons → POSITIVE (cation)
Electrons are the negative part. Take negatives away and the leftover protons win. An atom with 11 protons and 10 electrons is +1.
charge = protons − electrons
11 p+ − 10 e− = +1
Metals do this. They have few valence electrons, so dropping them is the short path to a full outer shell.
11 p+ − 10 e− = +1
+ Gain electrons → NEGATIVE (anion)
Add negatives and the electrons outnumber the protons. An atom with 17 protons and 18 electrons is −1.
charge = protons − electrons
17 p+ − 18 e− = −1
Nonmetals do this. They are already close to a full shell, so grabbing one or two finishes the job.
17 p+ − 18 e− = −1
And the ones that do neither. The noble gases in group 18 already have a full outer shell — 8 valence electrons (helium gets away with 2). There is nothing to gain and nothing worth losing, so they do not form ions and they almost never bond. Chemists call them inert. That full outer shell is the target every other atom on this page is chasing, which is why it has a name: the octet rule.
Sign in for your assignment
Sign in exactly as your name appears in the gradebook — that is how your teacher gives you credit.
Just here to practice on your own? Skip the sign-in — no name, no code, nothing sent to anybody.
Printable sheets
Black and white, no color ink needed. Each one opens your printer dialog — choose Save as PDF if you would rather keep a copy. Answer keys print as their own page, so print the student copy for them and the key for you.
Assign a set
Pick a set and share the link. Students sign in with name + period, answer questions built from their own name, and hand you a code. Each question gets one check — the first answer is the one that counts.
Grade assignment codes
Paste every student code below — one big mess is fine. You get a roster sorted by period, then last name.
Check one practice code
For free-practice codes (PPE-…) students earn outside an assignment.
Codes carry the student's name, set, score, and the date, so they cannot be swapped between students. Nothing is uploaded — everything runs on the device, and the page works with the wifi off.
Standards this covers
S8P1.a & S8P1.b — develop and use models of atomic structure; use the periodic table as a model to predict properties of elements based on their placement.
SPS1.a & SPS1.b — the arrangement of the modern periodic table; predict the properties and reactivity of an element based on group and period.
SPS2.a — how atoms gain or lose valence electrons to form ions, and why ionic bonds result.
SPS1.a & SPS1.b — the arrangement of the modern periodic table; predict the properties and reactivity of an element based on group and period.
SPS2.a — how atoms gain or lose valence electrons to form ions, and why ionic bonds result.
Where this sits in the unit. Run this page before Naming Binary Compounds — a student who cannot pull a charge off the table cannot criss-cross a formula. It pairs naturally with the Periodic Table Explorer, which is the reference; this page is the drill.