Chemistry Review
Name the three subatomic particles Proton, neutron, electron
What is the charge on each subatomic particle? Proton Neutron – 0 Electron -- -1
Complete this sentence: An atom is made of_____________, while a compound is made of ____________ one particle of one element more than one atom
Atomic number is ______________ and mass number is ______________ The number of protons The number of protons + neutrons
Isotopes differ in The number of neutrons
Ions differ in The number of electrons
Use your periodic table to write the symbol, atomic number, number of protons, neutrons, and electrons for iodine II 53 74 53
What are valence electrons? Electrons in the outer shell
Draw a Bohr atom for nitrogen
What makes atoms “happy”? What group are they like when they are happy? Having a full outer shell Noble gases (group 18)
How many valence electrons in Group 15? 55
How many valence electrons do transition metals have? number varies A Roman numeral is used to show how many when writing the names of compounds with transition metals
What is a row of the Periodic Table called? What is a column called? Row = period Column = Group or family
What is an anion? What is a cation? Anion = negatively charged ion Cation = positively charged ion
What is the charge on a nitrogen atom? How do you figure it out? -3 How many electrons it needs to get to a full outer shell of 8
Which groups form cations? Group 1, 2, 13 All the transition metals
Which groups form anions? Groups 15, 16, 17
Which group does not form ions at all? Why not? Group 18, the noble gases Because they are already happy
How do you know how many electrons an atom will gain or lose to form its ion? It will gain or lose the lowest number possible to form a complete outer shell (which is usually 8 but for a few of the smaller elements it is 2, like helium)
What kind of ions form an ionic compound? What keeps the ions together? a metal and a nonmetal They stay together because opposite charges attract
How do electrons move to form an ionic compound? How is that different from a covalent compound? ionic compound: electrons are transferred covalent compound: electrons are shared.
What kind of atoms form a covalent compound? Nonmetals with nonmetals (and hydrogen counts as a nonmetal)
What are the properties of ionic compounds? High melting point Dissolve in water Conduct electricity
Name this compound: BaO Barium oxide If the first element is Group 1, 2, or 13 (or silver, cadmium, or zinc) just name it with no Roman numeral The second element changes its name to end in -ide
Is this compound ionic or covalent? How do you know? P 2 O 5 Covalent because it is two nonmetals
How do you name this compound? CuO copper (II) oxide Oxygen has a -2 charge so it has to be balanced by +2 Copper is a transition metal so its charge varies—so it gets a Roman numeral
How do you write the formula for Tin (IV) Fluoride? SnF 4 Fluorine has a -1 charge. The Roman numeral IV tells you that tin has a +4 charge in this compound So to balance +4 there must be 4 fluorines of -1 each (4 x -1 = -4)
How do you name this covalent compound? C 2 P 6 Dicarbon hexaphosphide Use a prefix chart Prefix one = subscript one (if no subscript, no prefix) Name element one Prefix two = subscript two Name second element but change ending to - ide
Write the formula for this compound: hexasulfur monoxide S6OS6O Don’t write the subscript 1!
How many elements are in this compound? How many atoms? Ca 2 (NO 3 ) 2 3 elements: Ca, N, O You can tell because there are 3 capital letters 2 Ca, 2N (why?), 6 O (why?) = 10 atoms
How do you prove a chemical reaction has taken place? Do a chemical analysis to show that a new product has been formed
What is an aqueous solution? What kind of compounds form an aqueous solution? Aqueous = dissolved in water Ionic compounds dissolve in water to form aqueous solutions
What are the substances to the left of the arrow called in a chemical reaction? The substances to the right of the arrow? Left = reactants Right = products
How do you know if there is more than one reactant or product? There will be a plus sign
Which two types of chemical reactions are opposites of each other? Synthesis and decomposition
Which type of reaction always has CO 2 and H 2 O as products? Combustion
What type of chemical reaction exchanges ions in two compounds to form two new compounds? Double replacement
Which type of reaction is this? Al + H 2 SO 4 Al 2 (SO 4 ) 3 + H 2 Single replacement Because an element and a compound switch ions instead of two compounds
What type of reaction is this? Ba(OH) 2 BaO + H 2 O Decomposition Only one compound left of the arrow