The answer is aluminum foil. Milady explains why directly: "Aluminum foil is an example of a pure substance because it is composed only of atoms of the element, aluminum."
Concrete is the opposite kind of example — the textbook's own summary table lists concrete explicitly as a physical mixture, since it's made of water, sand, gravel, and dry cement combined, not a single element or compound. A pure substance has one consistent chemical composition throughout; a mixture, like concrete, doesn't.
Why this trips people up: this question was keyed to "concrete" in FadeJunkie's own bank until a July 2026 audit caught it — the real answer, aluminum foil, was sitting right there among the other choices the whole time.
Milady Standard Barbering, 6th ed., Ch. 7, p. 184: "Aluminum foil is an example of a pure substance because it is composed only of atoms of the element, aluminum. Concrete is an example of a physical mixture because it is composed of water, sand, gravel, and dry cement."
This is 1 of the real Science & Chemistry questions in FadeJunkie's Milady-sourced 300-question bank. See the Science & Chemistry practice questions page for a fuller sample, or try the Science & Chemistry practice quiz and flashcards for free. A one-time $15 lifetime pass unlocks the complete question bank across all 13 tested topics.
More real Science & Chemistry questions with sourced answers: What Do Nonaqueous Solutions Not Have.
Browse every topic on the Practice Question Hub, or see the Texas Barber State Board Exam Guide for the full exam process — required hours, PSI scheduling, and fees.