Law of Conservation of Mass and Energy
States of Matter
Classification of Matter
Properties and Changes
Interaction of Matter
Acids and Bases
Solid: has a definite shape and volume, the molecules are
very close together and vibrate very slowly in place.
Liquid: has a definite volume, but no definite shape. Liquids take the shape of their container. Molecules are further apart and move slowly.
Gas: has no definite volume and no definite shape. Molecules will move as far apart from each other as possible and move very fast.
Plasma: an electrically charged gas. Molecules move faster than a gas. The sun is made of plasma. Plasma can not usually be contained on earth with our current technology.
Kinetic Theory of Matter: When you add heat energy, molecules move faster and further apart. When you remove heat energy, molecules move slower and closer together. This is what causes matter to change from one state to another. For example, when you add heat energy to ice, the molecules move faster and further apart turning it into a liquid.
Evaporation: When a substance changes from a liquid to
Condensation: When a substance changes from a gas to a liquid.
Sublimation: When a substance changes from a solid to a gas, skipping the liquid phase (dry ice).
Boiling Point: The temperature at which a substance turns from a liquid to a gas.
Freezing Point: The temperature at which a substance turns from a liquid to a solid.
Melting Point: The temperature at which a substance turns from a solid to a liquid.
Elements: Pure substances made up of only one type of atom. All matter is made of atoms. The types of atoms or matter are listed on the periodic table of elements. Elements are represented by chemical symbols. Some examples are Cu for copper and H for hydrogen. Elements are pure substances and thus, are always a solid color. Mercury and Bromine are the only 2 elements that are a liquid at room temperature, the others are solids and gases.
Compounds: Pure substances made up of two ore more elements combined chemically. Compounds are represented by chemical formulas such as H2O for water and CO2 for carbon dioxide. Compounds that contain carbon are called organic compounds and compounds that do not contain carbon are called inorganic compounds. Compounds are pure substances and are thus, always one solid color.
Mixtures: Mixtures are not pure. They are made up of two or more substances combined physically, but are not chemically. Mixtures can easily be separated while pure substances can not. Some ways that mixtures can be separated is by sifting, using a magnet, evaporation, solubility, filtration, chromatography and distillation. Mixtures may or may not have the same composition throughout. Mixtures may be more than one color or a solid color. Any substance that is multicolored is a mixture.
Changes in Matter: Some changes occur spontaneously while
others require an outside force such as heat or light. These changes
may be classified as either a physical change or a chemical change.
Physical change: a change in the size, shape, or state of matter of the substance. No change occurs in the chemical composition of the substance. For example: tearing up paper, rolling tinfoil into a ball, breaking an egg, melting ice.
Chemical change: a process that changes the chemical composition of a substance. When a chemical change takes place, a chemical reaction between two or more substances occurs. A chemical reaction is a reaction in which a new substance or substances are formed. These new substances have different physical and chemical properties than the original substances. For example, oxygen can combine with hydrogen to form water. Water (H2O) is very different from both the oxygen and hydrogen. Evidence of a chemical change includes a new odor, a new color, fizzing, bubbling, heat or light given off, formation of a precipitate (a solid formed from two clear liquids).
-To help tell the difference between a chemical property and a chemical change: a chemical property is in the future tense (it can happen), a chemical change is in the present or past tense (it is happening or it happened)
Stirring, raising the temperature and crushing solids into smaller pieces all increase the rate of dissolving for a solution.
A solubility graph shows the rate that a solute dissolves in a solvent.
Ionic Solution: A solution with ions (atoms with a positive or negative charge) in it. Ionic solutions conduct electricity. The more concentrated the solution, the better the solution will conduct the electricity.
Atoms are the smallest unit of an element.
Atoms are made of three subatomic particles: protons, neutrons, and
electrons. The protons and neutron are located in the nucleus in
the center of the atom. The electrons move around the atom
in orbits similar to the planets going around the sun. This is also
called an electron cloud.
|Particle Type||Charge||Location in the atom||Mass|
|Proton||(+) positive||Nucleus||1 a.m.u.|
|Neutron||(0) neutral||Nucleus||1 a.m.u.|
|Electron||(-) negative||Electron Cloud||0 a.m.u.|
Maximum Number of Electrons per Energy Level
|1st energy level||2 electrons|
|2nd energy level||8 electrons|
|3rd energy level||18 electrons|
|4th energy level||32 electrons|
Mass Number: The mass number for an atom is equal to the number of protons plus the number of neutrons. Every proton and every neutron has an atomic mass of 1 a.m.u. (atomic mass units). Electrons have no mass. The average oxygen atom has 6 protons and 6 neutrons, 6+6=12, thus, oxygen has an atomic mass of 12 a.m.u. The average mass number for each atom is written on the periodic table of elements. To calculate the number of neutrons in an atom you use the formula:
Mass Number - Atomic Number = Number of Neutrons
Ions: Atoms with a positive or negative charge due to gaining or losing electrons.
Chemical symbols represent each element. A chemical symbol can be a Capital letter such as K for potassium or a capital and a lower case letter such as Ca for calcium.
Periods: the seven horizontal rows on the periodic table.
Elements on the first period have only one energy level, on the second
period they have two energy levels and so on.
Groups: Groups are also called families. They are represented by the vertical columns on the periodic table. Elements in the same group or family will exhibit similar chemical and physical properties. Elements in the same group usually have the same number of electrons in the outer most energy level or some other similar arrangement of electrons. Groups are numbered 1 - 18.
The atomic number and mass number is written in the box for each element. The atomic number is the smaller quantity and the mass number is the larger quantity
Know some characteristics and where the following is located on the
Metals: Located to the left of the zig zag line, but not including hydrogen, they tend to lose electrons, conduct heat and electricity easily, and are malleable.
Nonmetals: They are located on the right of the zig zag line, but they do not include Hydrogen. Nonmetals tend to gain electrons, do not conduct heat or electricity easily, are brittle, and a dull color.
Hydrogen: Hydrogen is set apart from other elements because its properties do not fit any single group. Sometimes it acts as a metal and sometimes it acts as a nonmetal. Hydrogen reacts easily with other elements.
Metalloids: These have some characteristics of metals and some characteristics of nonmetals. These are the elements that touch the zig zag line on the periodic table.
Transition Elements: Groups 3 -12 in the middle of the periodic table, most are hard and shiny, have high melting points, are good conductors, and are less reactive than the other metals,
Alkali Metals: Group 1, not including hydrogen, are very reactive. They have one electron in their outer most energy level, found only in nature as positively charged ions since the outer most electron is easily lost, they combine with negatively charged ions to form salts, soft, low densities, melt at low temperatures.
Alkaline Earth Metals: Group number 2, have 2 electrons in outer most energy level, occur in nature as ions , reactive, but not as reactive as alkali metals.
Rare Earth Elements: These are elements that are rarely found on earth or are created synthetically in a lab. They are located on the bottom of the periodic table, sometimes called rare earth metals.
Noble Gases: They are the group on the far right side of the periodic table in family number 18. These gases are very stable and do not usually react with other chemicals and are not combustible. They are stable because they have their outer most energy level filled. All the other elements want to be like a noble gas and have their outer most energy level filled.
Halogens: Group number 17, means "salt-former", combines with metals to form salts.
Radioactive Elements: Different tables have different symbols or ways of identifying these elements. The nuclei of radioactive elements are unstable and break down easily.
For each chemical formula count the number of elements, the number of
atoms for each element, and the total number of atoms in the molecule.
|Chemical formula||Number of elements||Number of atoms for each element||Total number of atoms in each molecule|
|NaNO3||3||Na=1 N=1 O=3||5|
Terms to know for chemical reactions:
Reactants: The chemicals you start with at the beginning
of the reaction. In the above example the reactants are 4H + 2O.
Products: The chemicals you have at the end of the reaction. In the above equation, the products are 2H20.
Subscripts: Describe the number of atoms for each element in the molecule. In 2H2O, the small 2 is the subscript. If there is not subscript, there is only one atom.
Coefficient: Describes how many molecules you have. In the example reaction, the following in bold were coefficients 4H + 2O2H20. We have 4 hydrogen and 2 Oxygen atoms in the reactants. We have 2 molecules of H2O in the products. To count the number of atoms, multiply the coefficient by the subscript. If there is no subscript, the subscript is equal to one. Two molecules of water or 2H2O are made of 4 hydrogen (2x2=4) and 2 oxygen (2x1=2) atoms.
The Law of Conservation of Mass states that in a chemical reaction matter
can neither be created or destroyed. Therefore, in a chemical reaction,
the number of atoms of each element must be equal on both sides of the
equation and the mass of the reactants must equal the mass of the products.
4H + 2O2H20
|Number of each type of atom for the reactants||H=4 O=2|
|Number of each type of atom for the products||H=4 O=2|
|Atomic mass of the reactants||36 a.m.u. (4*1=4 16*2=32 32+4=36)|
|Atomic mass of the products||36 a.m.u. (4*1=4 16*2=32 32+4=36)|
There are 4 main types of chemical reactions:
Synthesis or Composition Reaction: two or more substances combine together to form one larger substance.
Na + ClNaCl
Decomposition Reaction: One substance breaks down or decomposes into two or more smaller substances
NaClNa + Cl
Single Displacement Reaction: One element or set of elements replaces another element or set of elements in a compound.
Zn +Cu(NO3)2Zn(NO3)2 + Cu
Double Displacement Reaction: Elements or sets of elements trade partners with elements or sets of elements in another compound.
AgNO3 +NaClAgCl + NaNO3
An indicator is a substance that will produce a predictable change in color when it comes in contact with an acid or a base.
You can change the pH of a solution by adding acid (H+) or base (OH-). For example; if you have a swimming pool and you test the water and discover the pool is too acidic (too many H+ ions), you add base to the pool water (OH-).
If the .......
NaOH + HClNaCl +
Back to Home