Matter: Properties and Change

What is Matter?

Matter is anything that takes up space and/or has mass. Matter

is made up of atoms and molecules.

What are Atoms? What are Molecules?

Molecules are a group of atoms bonded together.

What is mass?Mass is how much matter an

object has*Mass is measured in grams

(g) or kilograms (kg)

• The building blocks of Matter• Consists of Protons (+), Electrons (-), and Neutrons (N).

• Consists of only one kind of atom, • Cannot be broken down into a simpler type of matter by either physical or chemical means• Can exist as either atoms or molecules.

Images are from http://www.chem4kids.com

• A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together. • In the animation above, two nitrogen atoms (N + N = N2) make one Nitrogen molecule .

Animated images and notes from http://www.chem.purdue.edu/gchelp/atoms/elements.html

• Atoms of two or more different elements bound together.

• Can be separated into elements chemically, but not physically.

In the animation above, water (H20) is a compound made of Hydrogen and Oxygen.

Elements

• An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made up of ONLY hydrogen atoms and oxygen is made up of ONLY oxygen atoms BUT the two elements can be combined to form compounds. For example, 2 hydrogen atoms can be combined with 1 oxygen atom to form the compound H20 (water).

The Periodic Table

• The periodic table is a table that lists the elements.

• The periodic table shows the symbols for the elements, their full names, their atomic numbers and their mass number.

• It organizes elements into groups and periods (columns and rows) based on their structure and properties.

Recognize that all of these elements that you see can combine in a multitude of ways to make up all the things in the universe.

All matter is made of moving particles called molecules

• The kinetic theory of matter states that all particles/molecules in matter are constantly moving.

• However, particles/molecules in solids, liquids, and gases have different characteristics.

Solid

Liquid Gas

• http://studyjams.scholastic.com/studyjams/jams/science/matter/solids-liquids-gases.htm

SolidsParticles/Molecules in a solid vibrate in fixed

positions but do not move past each other. The molecular bonds in a solid are very strong.

So, what are some characteristics of a solid?

Liquids Particles/Molecules in a liquid are not tightly

bound to each other as it is in a solid, molecules in liquid slide past each other.

So, what are the characteristics of liquids?

Gases Particles/Molecules in a gas are separated by

greater distances than those in a solid or liquid. The molecular bonds are the weakest in a gas.

So, what are the characteristics of gas?

FYI: There is a 4th state of matter called plasma…

Plasma is the most commonly seen state of matter in the universe.. A gas becomes a plasma when the addition of heat or other energy causes a significant number of atoms to release some or all of their electrons.

• Boiling point- is characterized by the formation of vapor bubbles within the liquid phase as a substance changes from a liquid to a gas.

• Melting point-Melting is a process that causes a substance to change from a solid to a liquid.

• Melting occurs when the molecules of a solid speed up enough that the motion overcomes the attractions so that the molecules can move past each other as a liquid.

• Melting and Freezing of a pure substance takes place at the same temperature.

• Boiling Point temperature is the same as the maximum condensing temperature.

•Changing from one state to another is a Physical Change.

•If a new substance is formed it is a Chemical Change.

Images are from http://www.chem4kids.com

Let’s go back to atoms for a moment…

• An atom is the most basic unit of matter. Atoms are composed of particles called protons, electrons and neutrons.

• As atoms can have different numbers of protons, electrons, and neutrons, this makes them elements.

• http://www.harcourtschool.com/activity/hotplate/index.html

• What is density– A property that describes the relationship

between mass and volume.

Density…

What determines whether one substance will sink or float when it is placed in another

substance?• If a solid or liquid is less dense than the liquid

it is placed in, it will float. If a solid or liquid is denser than the liquid it is placed in, it will sink. When two gases come into contact with each other, the less dense gas will rise, and the more dense gas will sink.

Density…

What is density and how is the density of a substance calculated?

• Density is a measurement of the amount of mass per unit volume of a substance. The more mass there is present in a unit volume, the denser a substance is. Density can be calculated by dividing a substance’s mass by its volume, using the following equation: d=m/v.

Physical properties of matter

• Density• Boiling point• Melting point• Solubility

Is a physical property of matter - In general, SOLUBILITY is the ability of a substance to dissolve. In the process of dissolving, the substance which is being dissolved is called a solute and the substance in which the solute is dissolved is called a solvent. A mixture of solute and solvent is called a solution. To put it in simple words:When we insert sugar into water it will dissolve. In this process:sugar is the solute water is the solvent

*The solubility of a substance can be changed under certain conditions.

• Solutions are groups of molecules that are mixed up in a completely even distribution.

• Uniform Distribution.• Example: Sugar and Water

Images are from http://www.chem4kids.com

• The substance to be dissolved.

• The one doing the dissolving.

Images are from http://www.chem4kids.com

• Particle sizes are in between the size of particles found in solutions and suspensions .

• Can be mixed and remain evenly distributed without settling out.

• They are substances held together by physical forces, not chemical.

• Can be separated physically.

• Solutions are also mixtures.

• The substances are not uniformly mixed.

• Example: Sand in a glass of water.Images are from http://www.chem4kids.com

• Are heterogeneous mixtures consisting of parts that are visible to the naked eye.

Example: the ingredients in salad dressing

• Substances will settle over time.

Convection• Convection is the process that transfers

energy in gases and liquids.• Hot air ________ and cold or cooler are

_______.• Why do hot liquids and gases rise and cooler

liquids and gases sink? Think about density…• When liquids and gases are heated, they

become less dense and therefore will rise above any material that is more dense.

Temperature and Heat6.P.3.1

Unit BChapter 2

Particles in a substance are not moving at the same speed and can change

speeds.

Temperature is a measurement of the

average kinetic energy of all particles in an object.

Temperature depends on the movement of

particles.

Heat is a flow of energy due to temperature

differences. And flows from higher temperatures

to lower temperatures.

Heat and Temperature are closely related but not the same…

• Temperature is the average kinetic energy of particles in a substance or location.

• Heat is a flow of energy from an object with a higher temperature to an object with a lower temperature.

Kinds of Heat transfer

• Heat Energy transfers in three ways.• Heat Energy can be transferred by conduction,

convection, or radiation.• Heat Energy is transferred between objects or

locations when there are temperature differences between them.

Conductors & Insulators

• Materials that easily transfer energy are conductors; those that are poor conductors are called insulators.

• Think about this question…• Why are pot and pan handles made out of plastic

or wood? • Why is the pan made of metal?• Why are coolers made out of types of plastics?

Good Conductors Poor ConductorsMetals Wood

PaperPlastic foam

Heat Transfer

Conduction

• Conduction is the process through which energy is transferred through physical contact.

• So, where is the physical contact? Think about what matter is made up of…

• Radiation is energy that travels as electromagnetic waves, such as visible light, and x-rays.

• ALL objects radiate at least a small amount of energy.

Radiation

- is a result of changes in temperature, matter changes in volume. Solids expand as the particles move ever so slightly farther apart.

Thermal Expansion