Stoichiometry and Matter

An element is a substance made from one type of atom. A compound is made from two or more types of atoms that are chemically combined.

Chemical reactions involving elements and compounds produce new compounds and often involve energy change. Atoms combine in fixed ratios to achieve a full outer shell of electrons.

The properties of a compound product can be very different from the reactants it was made from.

<p>A mixture is when elements and compounds are mixed together, but not chemically combined. They retain their original characteristics.</p> Signup and view all the answers

<p>Homogeneous mixtures have the same composition and properties throughout, while heterogeneous mixtures have different compositions and properties in different parts.</p> Signup and view all the answers

<p>A compound is made up of two or more types of atoms that are chemically combined, while a mixture is a combination of elements and compounds that are not chemically combined.</p> Signup and view all the answers

<p>Stoichiometric relationships in chemical reactions refer to the fixed ratios in which atoms combine to form compounds.</p> Signup and view all the answers

<p>A full outer shell of electrons refers to when an atom has its maximum number of electrons in its outermost energy level.</p> Signup and view all the answers

<p>Homogeneous mixtures have the same compositions and properties throughout, while heterogeneous mixtures have different compositions and properties in different parts.</p> Signup and view all the answers

<p>An example of a homogeneous mixture is air. It is considered homogeneous because the gases nitrogen and oxygen are uniformly distributed throughout, giving it a consistent composition and properties.</p> Signup and view all the answers