Matter in Our World

Matter

Made up of atomsAtoms that are all the same make an

element Every element has different types of atoms

ElementsElement Symbol Element Symbol

Hydrogen H Mg

Oxygen O Br

Sodium Na Nitrogen

K Sulfur

Iodine I Ca

C Boron

Chlorine Zn

Iron Si

Ag Neon

Matter

When elements chemically combine they form compounds The same element can combine Different elements can combine

Matter can be physically combined into mixtures Lots of elements in the same place Lots of compounds in the same place Combination of elements and compounds in the

same place

Matter

Elements, compounds, and molecules are all pure substances

Matter also exists as mixtures Homogenous

Mixtures that look the same throughout Substances are miscible

Heterogeneous Mixtures that you can see the different substances in Substances are immiscible

Matter

Chemical formulas are important for telling us what compounds are made of Sugar – C12H22O11

Carbon

12 atoms

Hydrogen Oxygen

11 atoms22 atoms

Common Compounds

Salt = NaCl Ammonia = NH3

Baking Soda = NaHCO3

Water = H2O Hydrogen Peroxide = H2O2

Bleach = NaOCl Glass = SiO2

Vinegar = CH3COOH

Kinetic Theory

Three main points All matter is made of atoms and molecules These atoms and molecules are always in

motion At high temperatures, particles move faster

At the same temperature, larger atoms and molecules move slower than smaller ones

Kinetic Theory

Used to describe the states of matter Solid Liquid Gas

Changing States

Solid

Atoms move very, very slowlySet volumeSet shape

States of Matter

Liquid

Atoms move aroundSet volumeChanging shapeCan look at viscosity

High viscosity = less flowing

States of Matter

Gas

Atoms move very, very fastChanging volumeChanging shapeExerts pressure on objects

High pressure = lots of movement

States of Matter

Changing States of Matter

Energy makes this happen

Red Energy added

Blue Energy taken

away

Changing States of Matter

Total amount of matter never changes Law of conservation of mass

Total amount of energy never changes Law of conservation of energy

Changes in Matter

Chemical change Changes the make-up of matter

Different matter is made

Physical change Does not change the make-up of matter

Same matter exists – just a different form

Clues to Chemical Change

Change in colorProduction of gasProduction of a solidKey words:

Burn, decay, ‘die’, ripen, rot

Clues to Physical Change

Key words Cut, tear, melt, freeze, dissolve, grind

Properties of Matter

Chemical Properties Only seen during chemical changes Describes how a substance reacts

Reactivity • How easily one substance can form another substance

Examples: flammability, reactivity, ability to tarnish, ability to decay

Properties of Matter

Physical Properties Can be seen without changing the object The same no matter how large or small the

object is

Examples: melting point, boiling point, color, density, smoothness

Density

Amount of mass within a certain amount on space

DensityVolumeMass

=

Density

What is the density of a 0.996 g piece of graphite with a volume of 0.44 cm3?

2.26 g/cm3

Density

A copper penny has a mass of 3.1 g and a volume of 0.35 cm3. What is the density of the penny?

8.86 g/cm3

Density

A bar of sliver has a mass of 68.0 g and a volume of 6.48 cm3. What is the density of silver?

10.49 g/cm3

Density

Sugar has a density of 1.59 g/cm3. What mass of sugar fits into a 140 cm3 bowl?

222.6 g

Density

The density of silver is 10.5 g/cm3. A bracelet made of silver has a volume of 1.12 cm3. What is the bracelet’s mass?

11.76 g

Density

Boron has a density of 2.34 g/cm3. What is the volume of 14.8 g of boron?

6.32 cm3

Density

Mercury has a density of 13.5 g/cm3. What is the volume of 4.62 g of mercury?

0.34 cm3

Density

The density of oak is generally 0.7 g/cm3. If a 35 cm3 piece of wood has a mass of 25 g, is the wood likely to be oak?

0.71 g/cm3