07 Chemistry and Scientific Reasoning Free Online FlashCards

What does chemistry study?

Chemistry studies matter—anything with mass and volume—and how its composition, properties, and interactions change.

How do an element and a compound differ?

An element is made of one kind of atom. A compound contains different elements chemically combined in a fixed ratio.

What defines a mixture?

A mixture contains substances physically combined in variable proportions. It may be uniform throughout or have visibly different parts.

What distinguishes a physical change?

A physical change alters a substance’s form or state without changing its identity; melting ice still leaves water.

What happens during a chemical change?

A chemical change forms new substances as atoms rearrange. Atoms are rearranged, not created or destroyed.

Why are bubbles not conclusive proof of a chemical reaction?

Gas formation, lasting color change, a precipitate, or energy change may indicate a reaction, but an observation alone is not proof; bubbles can also come from boiling.

How do accuracy and precision differ?

A useful measurement includes a number and unit and has some uncertainty. Accuracy is closeness to an accepted value; precision is agreement among repeated measurements.

How is density calculated?

Density is mass divided by volume: $\text{density}=\frac{\text{mass}}{\text{volume}}$. A sample of $12\,\text{g}$ with volume $4\,\text{mL}$ has density $3\,\text{g/mL}$.

What makes a hypothesis scientific?

A scientific hypothesis is testable and could be contradicted by evidence. Results may support it, but one experiment does not prove it forever.

What is a scientific theory?

A scientific theory is a broad explanation supported by extensive evidence, not merely a guess.

How do deductive and inductive reasoning differ?

Deductive reasoning derives a specific prediction from a general explanation; inductive reasoning identifies broader patterns from specific observations.

How do independent and dependent variables differ?

The independent variable is deliberately changed; the dependent variable is the response measured. For a tablet-dissolving test, temperature can be independent and dissolving time dependent.