Unit+2

=__**Chapter 2 Vocabulary**__= __Matter-__ anything that has mass and takes up space __Pure substance__- a substance that contains only one kind of matter, elements and compounds are pure substances __Homogenus Mixture__- a sample of matter consisting of more than one pure substance with properties that do not vary within the substance __Heterogenus Mixture-__ a mixture that is separated into different regions or phases that have different compositions or properties __Elements-__ any substance that can not be separated into smaller substances __Compounds-__ a pure chemical substance existing as two or more chemical elements __Physical Property-__ an aspect of an object or substance that can be measured or seen without changing its identity __Physical Change-__ any change not involving a change in the substances chemical identity __Chemical Property-__ any of a materials properties that become evident during a chemical reaction __Chemical Change-__ when bonds are broken and new bonds are created between new elements. __Endothermic Reactions-__ a process that absorbs energy in the form of heat (within heating) __Exothermic Reaction__ - a process or reaction that relapses energy in the form of heat, sometimes gives off light, electricity, or sound __Separation Techniques-__ =__**Practice Problems**__=
 * Distillation- Boiling water to separate mixtures
 * Density- separation by allowing the denser liquid to sink while the less dense one floats on top
 * Charcoal Filtration- absorbs a wide range of organic compounds dissolved or contained in gases or liquids
 * Particle Size- using sifting to separate mixtures, smaller particles fall through while the larger ones stay
 * Phase Change- Change a material's state of matter

**Decide if the following are physical or chemical changes**
Salt dissolves in water Physical, the chemical makeup of the salt is unchanged Ice Melts Physical, water and ice have the same chemical formula Metal rusting Chemical, the metal is oxidizing changing the chemical makeup of the metal Vinegar and baking soda make bubbles Chemical, the vinegar and baking soda react to form a new chemical

Decide if Mixture, pure substance, or compound
Nitrogen pure substance, Nitrogen is an elemet NaOH Compound, NaOH is 3 compounds bound together Salt Water Homogenous mixture, salt water is made up of one substance but not an element Pizza Heterogenous mixture, it is made up of more than 2 visible parts