Chemistry Grade 4. EQ: What is chemistry? Chemistry K-W-L KnowWant to KnowLearned

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

Bill Nye “Science Guy”

Atoms23 min

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.

Bill Nye “Science Guy”

Chemical Reactions

23 min

Gets Ready, Set, Dough