ATOMS AND THE PERIODIC TABLE
ATOMS Atoms are the building blocks of all matter. Atoms are comprised of a nucleus (at its center) and an electron cloud (surrounding the nucleus).
ATOMS SUBATOMIC PARTICLES Atoms are comprised of 3 subatomic particles. Protons found in the nucleus; positively charged Neutrons found in the nucleus; no charge Electrons found in the electron cloud; negatively charged; much smaller than protons and neutrons
ATOMS VALENCE ELECTRONS Valence electrons are found in the outermost energy level of the electron cloud (called the valence shell) and are the only ones involved in bonding. Determine: the chemical properties of an element reactivity the ability of an atom to undergo a chemical reaction with another atom
ATOMS VALENCE ELECTRONS 8 is the magic number if there are 8 valence electrons, the atom is stable and doesn t want to react with other atoms Hydrogen and helium are the exceptions. They only need 2 valence electrons for stability.
ATOMS Valence Shell
PERIODIC TABLE ELEMENTS An element is a substance that cannot be broken down into simpler substances by ordinary chemical changes and consists of only one kind of atom.
PERIODIC TABLE DIMITRI MENDELEEV The first scientist to notice the relationship between the elements was Dimitri Mendeleev. Mendeleev said that the properties of unknown elements could be predicted by the properties of the elements around the missing element.
PERIODIC TABLE The periodic table is a chart containing all of the elements arranged by atomic number and atomic mass. Each element is given a symbol. The table is designed to show patterns in the properties of the elements.
PERIODIC TABLE atomic number The number of protons in the element. 1 H 1.008 symbol Represents the element. Based on either the English or Latin name. atomic mass The mass of one atom. Can be used to find the number of neutrons. atomic mass - atomic number = # of neutrons
PERIODIC TABLE PERIODS Each row of the periodic table is called a period. The atomic number, atomic mass, and the number of valence electrons all increase from left to right. The transition metals are an exception because the number of valence electrons varies.
PERIODIC TABLE GROUPS/FAMILIES Each column of the periodic table is called a group or family. Each one is given a name to show the elements in the group share the same characteristics and behave the same way. Elements of the same group have the same number of valence electrons (except transition metals).
COLOR CODE YOUR PERIODIC TABLE! Using pgs. D20-21 (in the textbook) as a guide, color code your periodic table so that it shows the following: metals, nonmetals, and metalloids (you choose your own colors). Make sure you darken your metalloid stair steps! Create a color key and follow teacher s instructions for making it a cheat sheet for determining valence electrons.
PUT YOUR TABLE TO WORK... How many valence electrons does phosphorus (P) have? What is the symbol for magnesium? What is the atomic mass of copper (Cu)? How many protons does silicon (Si) have? How many total electrons does carbon (C) have? How many neutrons are in iron (Fe)? What state of matter is bromine (Br) at room temperature? Is calcium (Ca) a metal or nonmetal? How did you do?