Physical Change A change that alters the form or appearance of a substance but does ________________________________________________________________ Example: ripping paper, melting ice

Chemical Change A change in matter that produces _______________________________. Example: burning paper, mixing chemicals (alka seltzer and water)

Solutions Solution = _______________________ ________________________________________________________________ Example salt water

Solutions Uniform mixture = _________________ ________________________________ Solvent = ________________________ Solute = _________________________ May change phase Usually the smaller amount

Solutions Soluble = if a substance _________________ in another substance it is soluble Insoluble = if a substance _____________________ it is called insoluble Dilute = __________________, lots of solvent, little solute Concentrated = _____________________, lots of solute, little solvent Saturated = when ___________________ can be dissolved in the solvent

Acids and Bases Acids – Compounds begin with______ Example: Citric Acid, HCl, H2SO4 Turns Litmus paper ___________________ Examples: ___________________________ Bases – Compounds end in __________ Example: NaOH, KOH Turns Litmus paper _____________ Examples: ____________________________

Indicators and pH Indicator = something that turns __________ in the presence of a certain substance pH scale = a chart of acidity and basicity that goes from _____________

pH Scale 2 3 4 5 6 7 8 9 10 11 12 13 14 Strong weak neutral weak strong Acid acid base base Neutralization reaction: ________________________________________________________________________ Ex: HCl + NaOH -> H2O + NaCl acid base water salt

Chemical Reactions Chemical reaction = a process in which substances undergo chemical changes All chemical reactions either take in or give off energy. The energy is usually in the form of heat. Endothermic reaction: a reaction that __________________ in the form of heat. Exothermic reaction: a reaction that __________________ in the form of heat.