Physical science claims about forty percent of the GED Science test, and chemistry is its densest half. The good news: the test samples the subject at concept depth, not calculation depth. You will not balance equations from scratch or derive anything from the periodic table - you will identify what atoms do, predict how elements behave based on their position, recognize reaction patterns, and answer everyday questions about acids and batteries. One focused read gets you to test-ready chemistry.
Atoms in Two Paragraphs
Every atom contains a nucleus of protons (positive) and neutrons (neutral), wrapped in electrons (negative). The proton count - the atomic number - defines the element: six protons is always carbon. Electrons live in shells, and only the outermost shell participates in bonding. Atoms gain, lose, or share electrons to stabilize that outer shell, which is the entire engine of chemistry: metals tend to lose electrons, nonmetals tend to gain them, and sharing produces covalent bonds between nonmetals. Ions form when electrons are gained or lost, creating charged particles that attract oppositely charged partners - the salt in your kitchen is sodium ions glued to chloride ions by exactly that attraction.
Reading the Periodic Table
The table's layout encodes behavior. Columns - families - share properties: the far-right column is the noble gases, nearly inert because their outer shells are full; the column second from the left is the reactive metals that give away one electron; the column second from the right grabs electrons like it means it. Rows signal electron shells: each row down adds one, which is why atoms grow larger as you descend a group and smaller as you move right across a period, since the nucleus pulls harder on the same shell. The GED asks these trends qualitatively - which is larger, which is more reactive - and the family positions answer them without memorizing a single element card.
Reactions and Conservation
In a chemical reaction, bonds break and new ones form; atoms are rearranged, never created or destroyed. That conservation law is exam gold: count atoms on the left, count them on the right, and any answer choice violating the tally is wrong instantly. Synthesis combines simple substances into one; decomposition splits one apart; single replacement swaps one element into a compound; double replacement trades partners between two compounds. Combustion - fuel plus oxygen yielding carbon dioxide and water - shows up through its everyday cousins: burning wood, gasoline engines, candles. Physical changes (melting, dissolving) alter form without new substances; the test asks you to separate those from chemical changes like rusting or burning, and the distinction is always whether new material appears.
Acids, Bases, and pH
The pH scale runs 0 to 14: below 7 acidic, above 7 basic, exactly 7 neutral. Lower numbers mean more hydrogen ions floating free; higher numbers mean fewer. Battery acid and lemon juice sit low; bleach and oven cleaner sit high; pure water sits at 7. Acids taste sour and corrode metals (in fiction and labs alike); bases feel slippery and neutralize acids in reactions that produce water and salt - the classic baking-soda-and-vinegar fizz is carbon dioxide escaping that neutralization. The GED rarely calculates pH; it shows you a substance, asks where it lands on the scale, or asks what happens when an acid meets a base. Water's ability to buffer blood near 7.4 makes for a favorite homeostasis crossover question.
GED Chemistry - Frequently Asked Questions
Do I need to balance chemical equations on the GED?
No hand-balancing required, but you must recognize that atoms are conserved - answer choices that create or destroy atoms are wrong. Symbol-reading and prediction questions are the standard format.
How much chemistry is on the GED Science test?
Physical science is roughly 40 percent of the exam, and chemistry covers the majority of it: matter, reactions, periodic trends, and acids and bases appear on every form.
What chemistry should I memorize?
The pH scale endpoints, the conservation rule, periodic family positions, and the four reaction patterns. That short list covers essentially every chemistry item seen on official practice tests.
Chemistry sits inside the physical science block - see GED physics made easy for its partner half, and the Science help page for topic weights. If reading this felt like too much, our affordable GED service puts a professional test taker on the exam instead - $299, confidential, 98.6% pass rate.