CHEMISTRY FINAL REVIEW

Chemistry: The study of the composition, structure, and properties of matter and the changes it undergoes.

Matter: Anything that has mass and takes up space.

Physical Properties: Properties that can be observed or measured without changing the identity of the substance. Examples include color, density, melting point, boiling point, and state of matter.

Chemical Properties: Properties that describe the ability of a substance to undergo a chemical change. Examples include reactivity, flammability, and the ability to corrode.

Physical Change: A change in which the identity of the substance remains the same. Examples include changes in state (solid to liquid, liquid to gas), shape, and size.

Chemical Change: A change in which one or more new substances are formed. Examples include burning, rusting, and decomposition.

Solid: Has a definite shape and volume.

Liquid: Has a definite volume but takes the shape of its container.

Gas: Has no definite shape or volume; it fills its container completely.

Mixtures: A combination of two or more substances that are not chemically combined.

Homogeneous: A mixture that is uniform throughout. Examples include solutions like salt water and air.

Heterogeneous: A mixture that is not uniform throughout. Examples include oil and water, and a salad.

Element: A pure substance made up of only one type of atom.

Compound: A pure substance made up of two or more different elements chemically combined.

Periodic Table: A table that organizes the elements based on their properties.

Group/Family: A vertical column on the periodic table. Elements in the same group have similar chemical properties.

Period: A horizontal row on the periodic table.

Metals: Elements that are typically shiny, malleable, ductile, and good conductors of heat and electricity. Examples include iron, copper, and gold.

Nonmetals: Elements that are typically dull, brittle, and poor conductors of heat and electricity. Examples include oxygen, sulfur, and chlorine.

Metalloids: Elements that have properties of both metals and nonmetals. Examples include silicon and germanium.

Noble Gases: Unreactive elements in Group 18 of the periodic table. Examples include helium, neon, and argon.

Atomic Theory: A scientific theory that describes the structure of atoms.

Dalton's Atomic Theory: 1. All matter is made of atoms. 2. Atoms are indivisible and indestructible. 3. All atoms of a given element are identical. 4. Atoms of different elements are different. 5. Atoms of different elements combine in simple whole-number ratios to form compounds. 6. In a chemical reaction, atoms are rearranged, but they are not created or destroyed.

Rutherford's Gold Foil Experiment: An experiment that led to the discovery of the positively charged nucleus of the atom.

Nucleus: The small, dense center of an atom that contains protons and neutrons.

Protons: Positively charged particles in the nucleus of an atom.

Neutrons: Neutral particles in the nucleus of an atom.

Electrons: Negatively charged particles that orbit the nucleus of an atom.

Neutral Atom: An atom that has an equal number of protons and electrons.

* Metals generally have both low ionization energy and low electronegativity.

* Atomic radius decreases as you go down and to the left on the periodic table.

* Electronegativity - the strength of an atom's attraction for the electrons in a chemical bond. Electronegativity decreases as you go down the non metals and increases as you go up.

* Octet rule - elements want to have 8 valence electrons, in order to satisfy the octet rule you must have 8 electrons. For example 1s²2s²2p³ has a total of 7 electrons, in order to satisfy the octet rule it would need one more electron to equal 8.

* s,p,d,f are the shapes of orbitals.

* s - 2 electrons can occupy this orbital

* p - 6 electrons can occupy this orbital

* d - 10 electrons can occupy this orbital

* f - 14 electrons can occupy this orbital

Example Electron Configurations 1s²2s²2p⁶3s²3p⁶

For the above example 3p⁶ identifies the element as being found in row 3 of the p orbital and found in the 6 group of row 3p. So this element represents the element Argon. Argon is found in group 8A or group 18 and has all 8 valence electrons.

Examples of short hand and long version Electron Configurations:

A. Bromine - [Ar] 4s²3d¹⁰4p⁵ long version: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁵

B. Chlorine - [Ne] 3s²3p⁵ long version: 1s²2s²2p⁶3s²3p⁵

C. Flourine - [He] 2s²2p⁵ long version: 1s²2s²2p⁵

Aufbau Principle - electrons enter the lowest energy level first and that all lower energy levels are filled up to the last energy level.

* Ground state of electron configuration is regular electron configuration for example Ag has an electron configuration of [Kr] 5s1 4d10

* Visible light is the only part of the electromagnetic spectrum that can be seen by the human eye.

* The lowest energy shell that contains d orbitals is the shell n=3

* Electrons will absorb energy when jumping from 1 to the 3 orbit during the excited state.

* When an excited electron in an atom moves from the ground state, the electron absorbs energy as it moves to a higher energy state.

* Color from the flame test is emitted when electrons in the excited state return to lower energy states within the atom.

* Visible light- ROYGBIV Red, Orange, Yellow, Green, Blue, Indigo, Violet. Out of these colors red has the longest wavelength and violet has the shortest.

* The longer the wave length the lower the frequency and lower the energy. The shorter the wavelength the higher the frequency and higher the energy.

* Wavelength of visible light ranges from 400 to 780nm. The lower the number the greater the energy.

* Lewis structure is simply the valence electrons.

Isotopes: each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties. It's the same element with a different mass.

Atomic Number: the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

Atomic Mass or Mass Number: the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

To Calculate mass number add the protons and neutrons

Ionic Bond: electrostatic attraction between positive and negative ions; metal + non-metal

Covalent Bond: chemical bond when two atoms share electrons; non-metal + non-metal

Octet Rule: The octet rule states that atoms gain or lose electrons to attain an outer shell electron configuration nearest that of a noble gas. The attractive force between atoms is informally measured with this rule. Compounds tend to form so that each atom has an octet of electrons in its highest occupied energy level.

VSEPR: valence shell electron pair repulsion; the VSEPR theory is a model for predicting the shape of molecules