LECTURE: CHANGES IN MATTER AND THE CONSERVATION OF MASS

ALL MATTER CAN BE CHANGED BOTH PHYSICALLY OR CHEMICALLY.

PHYSICAL CHANGE OF MATTERWHEN MATTER UNDERGOES A PHYSICAL CHANGE IT IS STILL THE SAME SUBSTANCE.EXAMPLES:* CHANGES IT STATE OF MATTER (SOLID, LIQUID, OR GAS) STILL ONLY

PHYSICAL* CHANGES IN SHAPE OR FORM.

- BENDING- CRUSHING- DISSOLVING, - MOLDING

STILL ONLY PHYSICAL

A PHYSICAL CHANGE IN MATTER DOES NOT CHANGE THE CHEMICAL STRUCTURE.ICE WATER STEAMSOLID LIQUID GAS H2O H2O H2O

* PRODUCES A NEW SUBSTANCE WITH PROPERTIES THAT ARE DIFFERENT

THAN THOSE OF THE ORIGINAL SUBSTANCES.EXAMPLE:- NA (SODIUM) IS A METAL THAT IS GRAY COLORED- CL (CHLORINE) IS A GAS THAT

IS TOXIC

WHEN COMBINED THEY MAKE TABLE SALT.

CHEMICAL CHANGE OF MATTER

THE CONSERVATION OF MASS AND A CHANGE IN ENERGY OCCURS IN ALL PHYSICAL AND CHEMICAL CHANGES.

CONSERVATION OF MASS:

THE TOTAL MASS OF SUBSTANCE(S) REMAINS THE SAME(CONSTANT) REGARDLESS OF WHAT TYPE OF CHANGE OCCURS. EXAMPLE:* SOMETHING WITH A MASS OF 100G WILL REMAIN 100 GRAMS IF IT CHANGES PHYSICALLY OR CHEMICALLY

EVERY CHEMICAL AND PHYSICAL CHANGE IN MATTER INCLUDES A CHANGE IN ENERGY.

ENDOTHERMIC- A CHANGE IN ENERGY WHERE ENERGY IS ABSORBED OR TAKEN IN. MATTER GETS COLD.

EXOTHERMIC- A CHANGE IN ENERGY WHERE ENERGY IS RELEASED. MATTER GETS HOT.