Matter


Introduction to Matter Properties of Matter Weight vs. Mass Volume Displacement/Archimede's Principle Density Structure of Matter Phases of Matter Elements,Compounds, Mixtures Periodic Table

Matter is anything that has mass and takes up space. Mass is the measure of how much material is in an object. So almost everything is matter. The rule is, if you can touch it and its not energy, then it is matter.The building block of matter is the atom. That means that all matter is just varied combinations of atoms. A combination of two or more atoms that are bonded together chemically is called a molecule. It is smallest particle of substance that has the same properties as the substance.

A property is a characteristic that helps to identify an object. Example:
If I had a grain sugar and I began to cut it in half. The first time I did this I would be left with two smaller grains of sugar. But if I continued halfing the grains over and over again I would eventually get to a point such that if I cut one more time, what would be left, would not be sugar. It wouldn't look like sugar,taste like sugar, or even act or react like sugar. At this point(before the cutting) I would have one molecule of sugar (made of 6 atoms of carbon 12 atoms of hydrogen and 6 atoms of oxygen).

Some properties of matter/ characteristics that help to identify an objects are:
Mass-A measure of how much material is in an object
Weight-The measure of how hard gravity pulls on object
Density-A measure of how tightly the matter is packed into a given volume or a measure of how much mass of the substances is contained in a given volume. Density =mass/volume
Volume-The amount of space an object takes up.
Others include:
Shape
Taste
Smell
Feel
Color

It is easy to determine the shape,taste, smell, feel, or color of an object but mass ,weight, and density must be measured or calculated. Scientist prefer these properties because they are more concrete and easier to communicate.(quantitative)
Weight vs Mass
To determine mass a balance scale and standard counter weights must be used.
(pic from www.analyticalsci.com/science)
Weight, however,is the measure of how hard gravity pulls on object. The tool used to measure weight is a spring scale.
(pic from www.scientificsonline.com)
Weight can change due to the change in gravity. Mass does not change.
For example:
The moon's gravity is 1/6 that of Earth's. If I went to the moon my weight would be 1/6 that of what it was on the earth. My weight changed but did my mass change? No there is still just as much matter in me on the moon as there is here on earth.

Volume, the amount of space an object takes up, is measured or calculated.The tool used to measure volume of liquids is usually a graduated cylinder.
(pic from www.scientificsonline.com)

Displacement

Measuring the volume of an irregular solid is a bit more difficult.These are the steps.

1.Put enough water in the graduated cylinder to cover the object being measured
2. Record the volume of water.(This will be measure A)
3. Place the object that you wish to measure into the graduated cylinder.
4. The water level rose. Record as measure B.
5. B-A is the volume of your solid or the amount of water displaced is equal to the volume of the solid doing the displacing(Archimede's Principle). Displacement is the action that cause an amount of water to be pushed out of the way when something is inserted into it.

Volume of regular solids are calculated by using the formula
volume =LengthX Width X Height

Density is a measure of how tightly the matter is packed into a given volume or is a measure of how much mass of a substances is contained in a given volume.
Density =mass/volume.

Example:
A pound of lead is more dense that a pound of feathers. The masses are the same but the volume is much different.

Example2: An empty corked test tube compared to a corked test tube of mercury. The size/ volume of the test tubes are the same but their masses are different.

Density has to do with the relationship between mass and volume within an object. If substance a is less dense than substance b then substance a will float on / in substance a.

Phases of Matter

Matter has four states or phases.
Solid-State of matter that has a definite shape and volume due to the fact that its molecules pull strongly on one another.(molecules in a solid may vibrate but will not separate)
Liquid-Form of matter that has a definite volume but no definite shape due to the fact that the pull between the molecules are weaker than in solids.
Gas-Form of matter that has no definite shape or volume. The bonds between the molecules of a gas are very weak allowing them to escape from one another
Plasma-a very hot gas made of particles that have an electric charge
(Pic from http://www.chem.ufl.edu/~itl/2041_s02/lectures/lec_f.html)

Structure of Matter

Atoms are made of three subatomic particles.A subatomic particle is a particle smaller than an atom.


Name of the Particle	Charge	Location in the Atom
Proton	Positive	nucleus
Neutron	No charge	nucleus
Electron	Negative	shells around the nucleus

Valence electrons are the electrons in the outer most shell of an atom. These electrons are used in the bonding of elements to form compounds. These electrons can be shared, lost, or gained in this process.

(pic from http://www.spacesciencegroup.nsula.edu)
Most atoms have no charge or are refered to as neutral because the number of protons in them equals the number of electrons. The number of neutons can be determined by finding the element's atomic mass which is the number of protons + neutrons and subtracting the atomic number(the number of protons) from it.

Elements, Compounds, Mixtures

Elements are substances that cannot be broken down into other substances by chemical or physical means. They are pure substances made of only one kind of atom. Everything, all matter, is made up of a small number of existing elements. The known elements have been arranged and organized on a chart called The Periodic Table. Elements are chemically combined in ways to create new substances. This somewhat like the alphabet, 26 known letters. These letters can be joined to one another to produce an almost infinite number of words.

The number of neutrons in an element can be obtained by subtracting the atomic number from the rounded atomic mass or the mass number

Atomic Number
The number of protons in an atom defines what element it is. For example carbon atoms have six protons, hydrogen atoms have one, and oxygen atoms have eight. The number of protons in an atom is referred to as the atomic number of that element. The number of protons in an atom also determines the chemical behavior of the element.
Atomic Symbol:
The atomic symbol is one or two letters chosen to represent an element ("H" for "hydrogen," etc.). These symbols are used internationally. Typically, a symbol is the truncated name of the element or the truncated Latin name of the element. Click here for a list of the elements and their symbols.
Atomic Mass:
The atomic mass is the average mass of an element in atomic mass units ("amu"). Though individual atoms always have an integer number of atomic mass units, the atomic mass on the periodic table is stated as a decimal number because it is an average of the various isotopes of an element. Isotopes are forms of an element with a different number of neutrons.
The Mass Number
is realted to the atomic mass. It is the atomic mass rounded and tells the number of proton and neutons the elemant has.
Some use these two terms interchangebly.

Subatomic Particles
The three particles that make up atoms are protons, neutrons, and electrons. Protons and neutrons are heavier than electrons and reside in the "nucleus," which is the center of the atom. Protons have a positive electrical charge, and neutrons have no electrical charge. Electrons are extremely lightweight and are negatively charged. They exist in a cloud that surrounds the atom. The electron cloud has a radius 10,000 times greater than the nucleus.
The Nucleus
The nucleus of an atom is made up of protons and neutrons in a cluster. Most of the mass of the atom resides in the nucleus. The nucleus is held together by the tight pull of what is known to chemists and physicists as the "strong force." This force between the protons and neutrons overcomes the repulsive electrical force that would, according to the rules of electricity, push the protons apart otherwise.
Electrons
The electron is the lightweight particle that "orbits" outside of the atomic nucleus. Chemical bonding is essentially the interaction of electrons from one atom with the electrons of another atom. The magnitude of the charge on an electron is equal to the charge on a proton. Electrons surround the atom in pathways called orbitals. The inner orbitals surrounding the atom are spherical but the outer orbitals are much more complicated.
Chemical Bonding
Chemically bonding occurs when two particles can exchange or combine their outer electrons in such a way that is energetically favorable. An energetically favorable state can be seen as analogous to the way a dropped rock has a natural tendency to fall to the floor. When two atoms are close to each other and their electrons are of the correct type, it is more energetically favorable for them to come together and share electrons (become "bonded") than it is for them to exist as individual, separate atoms. When the bond occurs, the atoms become a compound. Like the rock falling to the floor, they "fall" together naturally.
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Compounds are considered pure substances made of two or more elements that have been chemically combined. They are not easily taken apart by nomal means. When two elements chemically combine the result or offspring of the combing may be vastly different from its parent elements. Example: Hydrogen and fire = Explosion. Oxygen and fire =Explosion. Two hydrogen atoms chemically combined to one oxygen atom = water. Water plus fire results in no explosion. The fire is either put out or the water turns to steam.
Mixtures-are two or more substances that are not chemically combined (Example- trailmix). In a mixture all the parts keep their properties. (Example -In trailmix the peanuts stay peanuts and the M&Ms stay M&Ms).
Types of Mixtures
Mixtures can be divided into two main subsets:
Heterogenous and Homogenous
Heterogenous mixtures do not appear to be the same throughout. fruitcake, trailmix, as well as oil and vinegar are all heterogeneous mixtures. The particles are large enough to be seen and can be separated from the mixture.
Homogeneous mixtures are very well mixed. Solutions are homogeneous mixtures. In a solution one substance is dissolved in another. The particles in a solution are atoms, ions, or molecules. The particles are obviously too small to be seen and will not separate out on standing. Solutions have two parts.
SOLVENT- THE SUBSTANCE WHICH DOES THE DISSOLVING SOLUTE- THE SUBSTANCE WHICH GETS DISSOLVED
(Example- coolaid- the water is the solvent the coolaid power and sugar are the solutes)
Water is often called the universal solvent because it dissolves so many materials. Substances (like oil) which do not dissolve in water are called insoluble.

Suspension- a heterogeneous mixture in which the particles are large enough to be seen by a microscope or the unaided eye (eventually, they settle out of the mixture). Example: stirring a teaspoon of dirt in a glass of water.

Colloid- a mixture where the size of particles in the mixture are between those of a solution and a suspension. NOTE: The particles appear evenly distributed. Examples: fog, cheese, butter, jellies, whipped cream. Often scatter light and are milky and translucent