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ChemistryGrade 4
EQ: What is chemistry?
Chemistry K-W-LKnow Want to Know Learned
History of ChemistryAncient Egyptians• Made perfumes for preserving the bodyAncient Greeks• Aristotle and other philosophers made detailed
observations about the four elements: earth, air, wind, and water
Middle Ages• Alchemists tried to find ways to help people live forever• Interested in turning lead into gold • The word "alchemy" comes from the Arabic word for
"the chemistry", originally from a Greek word meaning "fluids.”
Chemistry is the branch of science that studies the composition (make-up), properties, and behaviors of matter.
EQ: What are the three basic parts of an atom?
Atomsatom- the smallest unit of an element that still retains
the properties of the elementelectron- a negatively charged particle that circle the
nucleus of an atomcharge- the electrical energy contained in a particlenucleus- the center of an atomneutron- an uncharged or neutral particle in the
nucleus of an atomproton- a positively charged particle in the nucleus of
an atom (+)
Atom• Parts of an atom– proton– neutron– electron
Neutron
EQ: What are the three states of mattter?
States of Matter gas- a state of matter that both volume and shape change with
container.liquid-a state of matter that retains its volume, but shape changes
with containermolecule- two or more atoms that are chemically combinedphysical property- a characteristic that can be observed; color,
temperature, mass, volume are examplessolid- a state of matter that retains its shape and volume regardless
of the containertemperature- the measure of how hot or cold something isweight- the measure of the amount of gravity that acts on an
object; depends on an objects location in the universe
States of Matter
3 States• Solid
– Definite size– Definite shape
• Liquid– Definite volume– No definite shape
• Gas– No definite volume– No definite shape
Changing Between States of Matter
Processes:• Evaporation
– Changes a liquid to a gas
• Condensation– Changes a gas to a liquid
• Freezing– Changes a liquid to a solid
• Heating– Changes a solid to a liquid
EQ: What are the properties of matter?
Properties of Matter
density- the mass of a substance per unit of volumemass- the amount of matter in an objectmatter- anything that has mass and occupies spacevolume- the amount of space an object takes up or
occupies
EQ: What is density?
DensityExperiment
Archimedes Principle
If the object is less dense than water (if it floats on water), it displaces a weight of water equal to the weight of the object. If the object sinks in water, it simply displaces a volume of water equal to the volume of the object.
EQ: What is an element?
ElementsChemical SymbolChemical Name
Atomic Number
Atomic mass
Atomic number equals the number of ____________ or ________________.
Atomic mass equals the number of ______________ + _______________.
Assignment: Finish the rest of the worksheet and turn it in to your teacher.
EQ: What is a solution?
Solutionsconcentration- the amount of solute dissolved in a
solvent saturation point: the point at which no more of a
solute can be dissolved (cannot dissolve anymore)solute- any substance dissolved in a solvent (salt)solution- a homogeneous mixture of two or more
substances that are blended completely (lemonade)solvent- a substance, often a liquid, that can dissolve
another substance (water)
Making Crystals
Materials:• Cup • Straw• String• Hot water
– H2O
• Sugar (C12H22O11)
• Teaspoon• Thermometer
Procedure:1. Fill a cup ½ full with solvent (hot water). Measure and
record the temperature of the solvent.2. Measuring 1 teaspoon at a time, add solute (sugar) to
the water. Dissolve completely by stirring before adding another teaspoon of solute.
3. When the solvent becomes saturated, record the concentration (amount of sugar).
4. Tie a string to the center of the straw.5. Hang the string down into the solution (sugar + water)
and allow the straw to rest across the cup rim.6. Carefully put the cup of solution in a warm location
for several days.7. Observe results.
