PROF. LIRIETT HERRERA

SCIENCE : 7TH GRADE

APRIL 20, 2012

EVERYTHING THAT

SURROUNDS US IS

MADE UP MATTER.

THE AIR, ROCKS,

ANIMALS, PLANTS,

EVERYTHING.

WE COULD DEFINE

MATTER AS ALL THAT

OCCUPIES A SPACE

AND CAN BE WEIGHED.

ALL MATTER IS MADE UP

ATOMS, INDEPENDENTLY OF

ITS PHYSICAL STATE.

ATOMS COM E TOGETHER TO

FORM MOLECULES.

ATOMS ARE MADE UP OF

EVEN SMALLER PARTICLES:

PROTONS, NEUTRONS AND

ELECTRONS.

SOLIDS: THEY HAVE

GENERALLY A FIXED SHAPE ,

FIXED VOLUME AND THEY ARE

DIFFICULT TO COMPRESS.

LIQUIDS: THEY HAVE NO

FIXED SHAPE AND THEY HAVE

A RELATIVELY FIXED VOLUME.

GASES: THEY HAVE NO FIXED

SHAPE, QUITE LOW DENSITY,

CAN BE COMPRESSED VERY

EASY AND EXERT PRESSURE

AGAINST WALLS OF A

RECEPTACLE.

WE COULD MEASURE MATTER

USING THE INTERNATIONAL

SYSTEM OF UNITS (SI)

LENGTH: IS THE DISTANCE

BETWEEN TWO BODIES.

IN UNITS THIS IS MEASURED IN

METRES, CENTIMETERS OR

KILOMETERS.

SURFACE AREA: IS THE SPACE

OCCUPIED BY TWO DIMENSIONS

LENGHT AND WIDTH. IN UNITS

WE MEASURE THIS IN SQUARE

METERS, CENTIMETERS.

VOLUME: IS THE TOTAL SPACE

OCCUPIED BY A BODY. WE

MEASURE IT BY CUBIC METER.

MASS: IS THE AMOUNT OF

MATTER IN A BODY. IT IS

MEASURE IN KILOGRAMS AND

GRAMS.

DENSITY: IN SOME WAY

MEASURES NOW

CONCENTRATED THE MASS IS.

THE DENSITY OF SOLIDS IS,

HIGHER THAN THE LIQUIDS,

AND THE DENSITY OF LIQUIDS

IS HIGHER THAT GASES.

TEMPERATURE: IS RELATED

TO THE AMOUNT OF HEAT

THAT A BODY CAN GIVE OFF

OR BOTH.

THE MATTER THAT SURROUND

US IS VERY VARIED, AT LEAST

IN APPEARANCE.

PURE SUBSTANCES: ONLY HAVE

ONE COMPONENT. ARE PURE

SUBSTANCES. THEY ARE

HOMOGENOUS TO LOOK AT AND

THEY HAVE A UNIFORM

COMPOSITION.

MIXES SUBSTANCES: ARE MADE

UP TWO OR MORE DIFFERENT

SUBSTANCES. THE MIXTURES

ARE HETEROGENEOUS OR

HOMOGENEOUS MIXTURES..

MATTER

PURE

SUBSTANCES MIXTURES

HETEROGENEOU

SHOMOGENEOUS

SOLUTIONS

A SOLUTION IS ANY

HOMOGENEOUS MIXTURE.

EXAMPLE;

AIR IS A SOLUTION

IN WHICH ALL THE

COMPONENTS ARE GASES

(NITROGEN, OXYGEN AND

ARGON)

BRONZE: IS AMIXTURE OF

COPPER AND TIN.

STEEL: IS A MIXTURE OF

IRON AND CARBON.

MIXTURES COMPONENTS

AIR NITROGEN, OXYGEN,ARGON

STEEL IRON AND CARBON

SEA WATER WATER, SALT, OXYGEN

GRANITE VARIOUS MINERALS

COMPONENTS OF SOME MIXTURES