Unique Characteristics of Matter

7/27/2019 Unique Characteristics of Matter

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Second Term

Grade 9 Science



What’s the MATTER?



Learning Tasks

Recap

Activity

Unique Characteristics of Matter Self Check!

Assignment



Activity!

Choose and classify 3 items from your bag

How are you able to differentiate eachone?

What makes each of them unique?



Module 17: UniqueCharacteristics of Matter

Matter have characteristics that can beused not only to describe them but also toidentify them.

Characteristics that are unique to aparticular material are called properties



Density

The amount of matter in a given volumeof material

An indication of how compact a givenmatter is.

STYROFOAM BALL vs. A PIECE OF LEAD

Expressed in the unit: gram per cubiccentimeter (g/cm3)

Computed using this formula: D=m/V



D=m/V

Density=Mass ÷ Volume

Measure the mass of the object using abalance.

To measure the volume, you can use thedisplacement method (measure the amount of liquid without the object, place the object inside

and measure the volume again. Subtract theinitial measurement from the final one).



Take Note:

The density of a pure substance isdependent on the size and thearrangement of the atoms in the

substance.

Every substance has a specific density,which can be used to identify a substance.



List of Densities



Analyze this:

Which is denser, 1 g of gold or 1 kg of copper? Why?

Which will have greater volume, 1 kg of copper or 1 kg of iron?



Effect of Density

Objects which are denser than water sink,while those that are less dense, float.

– A fluid will float on another fluid that is denser

– Balloons float because they are filled withhelium, a gas that is less dense than air.

– The density of the seeds (palay or mongo)

will float if it is a bad seed.



Density vs Buoyancy

An object floats on a liquid even if it isdenser than the liquid because of buoyantforce.

This force, which acts on the object, isequal to the weight of the fluid that theobject displaces.

Ex. A nail sinks when thrown on aswimming pool, but a ship (heavier) floatson an ocean.



Melting Point

The temperature at which a solid turnsto liquid

Melting point are at different temperatures(page 141-142, Module 17: Chart)

– Ex. Ice: Melts at 0 degrees Celsius



Boiling Point

When any substance boils, it changesfrom liquid to gas. The temperature atwhich a liquid changes into gas is

known as the boiling point.

Like melting, it also requires the additionof heat.

Ex. Water: 100 degrees Celsius



Some properties of metals

Metals have many properties that makethem useful both at home and inindustries.

Can you give some examples of appliancesmade of metal?

What properties make metals so useful?



Thermal and ElectricConductivity

Metals have high thermal and electricalconductivity

Cookware is often made of aluminum orsteel so that heat is easily conducted tothe food.

Copper and aluminum are used inelectrical wires since they are goodconductors of electricity.



Malleability

can be pounded and shaped into very thinsheets without breaking

Examples:

Gold and silver’s malleability make themideal to use for jewelry.

When aluminum is stretched out into verythin sheets, you get aluminum foil.



Ductility

Can be stretched into wires or threads

Acts like clay, changes shape when it isstretched

Does NOT go back to its original shape

Examples:

Copper and aluminum wires used inelectrical wiring



SW#4: Self Check! (T/F)

1. The properties of each substance can be usedto identify them.

2. A given substance will always float if it is more

dense than the fluid it is in.3. A buoyant force makes heavy objects float.

4. Melting point is the point where liquid matterbecomes gas.

5. A metal is malleable if it can be stretched intowires.



6. Aluminum foil is an example of malleability.

7. Good conductors of heat and electricity meansthat it does not let heat and electricity pass

through.8. The boiling point of water is 100°C

9. The melting point of water is 0°C

10. Density = m/V, where mass is the amount of matter present in an object, and volume is theamount of space the matter occupies.

Unique Characteristics of Matter

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