Compounds and mixtures

Front

Matter Noun

---

[mat-er]

Back

Matter

---

Anything that possesses mass and takes up space, which constitutes all observable physical substances in the universe.

---

Example: Matter exists in different states (solid, liquid, gas), which are defined by the arrangement and movement of their particles, as shown for water.

Front

Pure Substance Noun

---

[pyoor sub-stuhns]

Back

Pure Substance

---

A form of matter with a constant chemical composition and distinct properties that cannot be separated by physical means.

---

Example: Gold is a pure substance because it is an element, meaning it is made up of only one type of atom.

Front

Mixture Noun

---

[miks-cher]

Back

Mixture

---

A combination of two or more substances that are not chemically bonded and can be separated by physical methods.

---

Example: This diagram shows a solution, a type of mixture where one substance (the solute) is evenly dissolved and spread throughout another (the solvent).

Front

Element Noun

---

[el-uh-muhnt]

Back

Element

---

A pure substance consisting of only one type of atom that cannot be broken down into simpler substances by chemical means.

---

Example: This diagram shows an atom of the element Oxygen, which is made of only one type of atom with 8 protons in its nucleus.

Front

Compound Noun

---

[kom-pound]

Back

Compound

---

A pure substance containing two or more different elements chemically combined together in a fixed, definite proportion.

---

Example: This diagram shows a molecule of carbon dioxide (CO₂), a compound made of one carbon atom chemically bonded to two oxygen atoms.

Front

Heterogeneous Mixture Noun

---

[het-er-uh-jee-nee-uhs miks-cher]

Back

Heterogeneous Mixture

---

A type of mixture in which the composition is not uniform throughout and its individual components remain physically distinct.

---

Example: This diagram shows that when oil and water are mixed (agitated), they form a heterogeneous mixture where oil droplets are visible and not evenly distributed.

Front

Homogeneous Mixture Noun

---

[hoh-muh-jee-nee-uhs miks-cher]

Back

Homogeneous Mixture

---

A type of mixture, also known as a solution, in which the composition is uniform throughout the entire substance.

---

Example: This diagram shows a solution where solute particles are uniformly distributed in a solvent, making it a homogeneous mixture because its composition is the same everywhere.

Front

Atom Noun

---

[at-uhm]

Back

Atom

---

The basic and smallest unit of a chemical element that retains the unique properties of that specific element.

---

Example: This Bohr model shows a Sodium atom, the basic unit of matter, with its nucleus (Na) and electrons arranged in shells (2, 8, 1).

Front

Molecule Noun

---

[mol-i-kyool]

Back

Molecule

---

An electrically neutral group of two or more atoms that are held together by strong chemical bonds.

---

Example: This diagram shows a single water molecule, where two hydrogen (H) atoms are chemically bonded to one oxygen (O) atom, forming a compound (H₂O).

Front

Physical Property Noun

---

[fiz-i-kuhl prop-er-tee]

Back

Physical Property

---

A characteristic of a substance that can be observed or measured without changing the substance's chemical identity.

---

Example: A substance's state of matter (solid, liquid) is a physical property. Water changes state by melting or freezing, but it remains the same compound.