Elements and Compounds

Front

Matter Noun

---

[mat-er]

Back

Matter

---

Anything that has mass and takes up space, composing all physical objects in the known universe.

---

Example: This image shows the three common states of matter—solid, liquid, and gas—by illustrating how particles are arranged and move in each state.

Front

Pure Substance Noun

---

[pyoor sub-stuhns]

Back

Pure Substance

---

A form of matter that has a definite chemical composition and distinct properties throughout its entirety.

---

Example: These gold bars represent a pure substance because they are made of only one type of element: gold (Au).

Front

Element Noun

---

[el-uh-muhnt]

Back

Element

---

A pure substance consisting of only one type of atom, which cannot be broken down by chemical means.

---

Example: This diagram shows a single Oxygen atom, the basic unit of an element. All atoms of the element oxygen have 8 protons.

Front

Chemical Symbol Noun

---

[kem-i-kuhl sim-buhl]

Back

Chemical Symbol

---

A one or two-letter abbreviation used to represent a chemical element in formulas and equations.

---

Example: This image shows the element Oxygen's tile from the periodic table. The large letter 'O' in the center is the chemical symbol for Oxygen.

Front

Periodic Table Noun

---

[peer-ee-od-ik tey-buhl]

Back

Periodic Table

---

A tabular chart that arranges all known chemical elements based on their atomic number and recurring properties.

---

Example: This image displays the periodic table, a chart organizing all known chemical elements by their atomic number, with a key explaining how to read each element's information.

Front

Atom Noun

---

[at-uhm]

Back

Atom

---

The smallest fundamental unit of an element that retains the chemical properties of that specific element.

---

Example: This diagram shows an atom's basic structure: a central nucleus with protons and neutrons, orbited by electrons in distinct electron shells.

Front

Nucleus Noun

---

[noo-klee-uhs]

Back

Nucleus

---

The small, dense, positively charged central region of an atom, composed of protons and neutrons.

---

Example: The nucleus is the dense, central core of an atom, containing positively charged protons and neutral neutrons, as shown in this model.

Front

Proton Noun

---

[proh-ton]

Back

Proton

---

A stable subatomic particle with a positive electric charge, found within the nucleus of an atom.

---

Example: This diagram shows a proton, a particle with a positive charge (+), located inside the nucleus of an atom along with neutrons.

Front

Neutron Noun

---

[noo-tron]

Back

Neutron

---

A subatomic particle with no net electric charge, found within the nucleus of an atom.

---

Example: This diagram shows a neutron, a particle with no charge, located inside the atom's central nucleus along with protons.

Front

Electron Noun

---

[ih-lek-tron]

Back

Electron

---

A stable subatomic particle with a negative electric charge that orbits the nucleus of an atom.

---

Example: This diagram shows an atom's structure, where electrons are the small particles that orbit the central nucleus, which contains protons and neutrons.