Chemistry - 1st Semester Final Review - 2024.docx

Matter

Anything that has mass and takes up space.

Chemistry

The study of matter, its properties, and the changes it undergoes.

Worldview

The overall perspective from which one sees and interprets the world.

Hypothesis

A testable prediction about the outcome of an experiment.

Physical property

A characteristic of a substance that can be observed without changing its composition.

Physical change

A change that affects one or more physical properties of a substance without altering its chemical composition.

Chemical property

A characteristic of a substance that can only be observed during a chemical reaction.

Chemical change

A change that occurs when one or more substances change into entirely new substances with different properties.

Atom

The smallest unit of an element that retains the properties of that element.

Pure substance

A form of matter that has a constant composition and properties throughout.

Element

A pure substance that cannot be broken down into simpler substances by chemical means.

Compound

A substance formed when two or more elements are chemically bonded together.

Mixture

A combination of two or more substances that are not chemically bonded.

Homogeneous Mixture

A mixture that has a uniform composition and properties throughout.

Heterogeneous Mixture

A mixture that does not have a uniform composition and properties.

Monatomic elements

Elements that consist of single atoms.

Diatomic elements

Elements that consist of two atoms, which may be of the same or different elements.

Melting

The phase change from solid to liquid.

Freezing

The phase change from liquid to solid.

Condensing

The phase change from gas to liquid.

Evaporation

The phase change from liquid to gas.

Sublimation

The phase change from solid to gas without passing through a liquid state.

Deposition

The phase change from gas to solid without passing through a liquid state.

Significant Figures

Digits in a number that carry meaningful information about its precision.

Accuracy

The closeness of a measured value to a standard or known value.

Precision

The closeness of two or more measurements to each other.

Density

The mass per unit volume of a substance.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Ions

Atoms or molecules that have a net electric charge due to the loss or gain of one or more electrons.

Cation

A positively charged ion formed by the loss of electrons.

Anion

A negatively charged ion formed by the gain of electrons.