M IND O VER M ATTER Explain p.73-79. E NTRY T ASK Begin a new header/thread in your notebook “Mind over matter” Write the Learning Target: I can explain.

MIND OVER MATTERExplain p.73-79

ENTRY TASK

Begin a new header/thread in your notebook “Mind over matter”

Write the Learning Target: I can explain that the densities of various substances are related to differences in the particles that make them up.

Skills: I can calculate density given mass and

volume. I can use a substance’s density and volume

to calculate mass. Update your Table of Contents

ENTRY TASK

MIND OVER MATTER

Read the Introduction p. 73Read “Density” p. 74-75 & Take Notes.Be able to define:DensityThe relationship between 1 mL and 1 cubic centimeter (cm3)The units normally used to report densityPhysical PropertyIntensive PropertyExtensive Property

MIND OVER MATTER

Density is the ratio of a material's mass to the volume it occupies.

g/mL or g/cm3

g/mL is the same as g/cm3 because a 1g cube that is 1cm on each side will displace Exactly 1mL of water

This ratio is constant for a given substance, for constant temperature and pressure.

This means that the density is the same regardless of the sample size of your substance (if pressure and temperature don't change)

MIND OVER MATTER

Example: 3 rings have the following densities:

silver ring density = 10.5 g/cm3

gold ring density = 19.3 g/cm3

platinum ring density = 21.1 g/cm3

If each ring has a mass of 6 grams, how do they compare in size (smallest to largest)?

MIND OVER MATTER

If each ring has a mass of 6 grams, how do they compare in size (smallest to largest)?

In order of their densities: silver ring density = 10.5 g/cm3 (lowest) gold ring density = 19.3 g/cm3

platinum ring density = 21.1 g/cm3 (highest) If all 3 rings have the same mass, then the

volume (size) must be different: As the density increases, the volume

decreases. Platinum (smallest); Gold; Silver (largest)

MIND OVER MATTERMacroscopic View: We can see density

differences: by observing how substances behave together a candle floats in isopropyl alcohol a candle sinks in water oil floats on water the candle acts differently because each liquid

has a different density.

MIND OVER MATTERMacroscopic View: We can see density

differences: on a graph of mass vs. volume

steeper slope = higher density

MIND OVER MATTER

Physical Property - a property of a material or substance that can be observed or determined without changing the identity of the material.

Intensive Property - a property whose value is independent of the amount of material tested.Examples: temperature, pressure, viscosity,

density, melting point, boiling point Extensive Property - a property whose value

depends on the size or amount of material testedExamples: mass, volume, length, heat, energy,

electrical resistance

MIND OVER MATTER

Answer P&P #2a,b,c pg. 75/76 in your notebook! Show all your work.

AN INTERVIEW WITH DEMOCRITUS

Ancient Greek Science roleplay Read pg. 76-78. Be able to define and explain the

following:AtomElementCompoundMoleculePure substanceMixture

AN INTERVIEW WITH DEMOCRITUS Democritus was a greek philosopher and

scientist from 400 BC. Didn't have fancy equipment and tools to run

tests and experiments Relied on "thought experiments" - using

imagination to logically reason through a problem

Democritus thought about what it would mean if he took a gold cube and kept cutting it in half into smaller and smaller pieces.

the density and characteristic properties of each smaller piece would remain the same because they were still pieces of gold

AN INTERVIEW WITH DEMOCRITUSat some point he would reach the smallest piece that would still retain the characteristics of gold.

The smallest piece was called "atomos" (cannot be further divided)

Atom = fundamental unit of matter

AN INTERVIEW WITH DEMOCRITUSelement - a substance composed of

atoms having an identical number of protons in each nucleus. An element cannot be reduced to simpler substances by normal chemical means.

atom - the smallest unit of an element/ the fundamental unit of matter

compound - a substance formed by the combination of atoms of one or more elements

AN INTERVIEW WITH DEMOCRITUSmolecule - an electrically neutral

group of two or more elements held together by chemical bonds.

pure substance - a substance that can be divided down to a single atom or a single molecule. Pure substances always have the same characteristic properties.

mixture - physical combinations of substances. Mixtures may have some of the same properties of the constituent substances, but often have new properties.

REFLECT & CONNECT

Complete R&C #1-3 p. 79

REFLECT & CONNECT #1 Question: According to the ideas of

Democritus, what might account for 1cm3 of one substance being heavier than 1cm3 of another substance?

Democritus said that all matter was made up of tiny particles called atoms. He believed that the atoms that made up one substance were different from the atoms that made up another substance. He also believed that if one substance had a greater density, then that atoms that make up that substance must have a greater mass than those that make up the other substance.

REFLECT & CONNECT #1

Do you think that's the whole story? Diamonds and graphite are both made of atoms of carbon, yet they have different densities. Can you think of some reasons why?

REFLECT & CONNECT #1

REFLECT & CONNECT #2

2. The densities of most woods are reported as a range of values. The densities of most pure metals, such as silver and platinum, are reported as a single value. Why?

Trees are alive and grow. Metals are not! Trees soak up water and their growth varies from year to year, so their densities are not a "set" value.

REFLECT & CONNECT #3

3. Ice floats in water, but sinks in rubbing alcohol. Draw sketches representing these observations at the microscopic level