Atoms, Elements and Compounds Flashcards

Flashcards for Atoms, Elements, and Compounds Summary

Pure Substance

Made of one type of particle and cannot be physically separated.

Element

One type of atom (e.g., gold = Au)

Compound

Two or more types of atoms chemically bonded (e.g., H2O = hydrogen + oxygen)

Mixture

Two or more substances physically mixed (e.g., saltwater) and can be physically separated.

Homogeneous Mixture

Looks the same throughout (e.g., air).

Heterogeneous Mixture

Looks different throughout (e.g., salad).

Atoms

Tiny particles with protons (+ charge), neutrons (0 charge), and electrons (- charge)

Nucleus

The center of an atom and holds the protons and neutrons.

Atomic Number

Number of protons in an atom.

Atomic Mass

Protons + Neutrons

Protons

Particles with a positive charge

Neutrons

Particles with a neutral charge

Electrons

Particles with a negative charge

Molecule

Made out of two or more of the same type of atom.

Physical Change

A change that does not alter the chemical composition of a substance (e.g., ice melting, boiling water, cutting paper).

Chemical Change

A change that results in the formation of a new substance and cannot be easily reversed (e.g., burning paper, iron rusting, cooking an egg).