What is the difference between a physical property and a chemical property?
A chemical property has to do with how a substance may react (reactivity or combustability).
Physical properties describe a substance's size, color, odor, texture, etc.
What are the three main subatomic particles?
Protons, neutrons and electrons
How do you name a binary ionic compound?
Name of metal ion (may have a Roman numeral) and then name of the nonmetal ion (ide ending).
What type of compound does the formula NaCl represent?
Binary ionic compound (metal + nonmetal)
How can you identify a synthesis reaction?
Synthesis reactions have only one product.
Why is it important to balance chemical equations?
Chemical reactions actually follow the law of conservation of mass. Substances can not appear out of nowhere and do not just disappear.
Give an example of a physical change.
There are many answers.
Examples: cutting, melting, dissolving...
What is the charge of a proton?
Positive one per proton
What is the name of CaCl2?
calcium chloride
Write the formula for a compound formed from one sulfur and three oxygen atoms.
SO3
Describe a decomposition reaction.
Decomposition reaction have only one reactant.
Balance the equation: H2 + Cl2 → HCl
H2 + Cl2 → 2HCl
What is density and how is it calculated?
Density is a characteristic physical property of a substance that is the ratio of mass to volume.
Explain the Bohr model of the atom.
Proton and neutron numbers written in the middle, surrounded by energy levels that have electrons in concentric circles.
How would you name a binary covalent compound?
First nonmetal has Greek prefix matching formula's subscript (except "mono") with normal element name followed by Greek prefix on second nonmetal with name containing ide ending.
Write the formula for aluminum chloride.
AlCl3
What is a single replacement reaction?
One element replaces an element in a single replacement, so you always have an element and a compound in the reactant and a different element and compound in the product side.
Balance the equation: Mg + O2 → MgO
2Mg + O2 → 2MgO
Describe the difference between a solid, liquid, and gas in terms of particle arrangement.
Solid phase has particles tightly packed and moving very little.
Liquid phase has more particle motion that solid, but particles are not completely free. A liquid will take the shape of a container.
Gas molecules move the fastest and break free from each other. Gas particles fill the whole space.
How many electrons can fit in the second energy level of an atom?
8
What is the correct name for P2O5?
diphosphorus pentaoxide
What is the formula for gallium oxide?
Ga2O3
What are the products of a combustion reaction?
carbon dioxide (CO2) and water (H2O)
How do you approach balancing a chemical equation for combustion reactions?
1. Start with carbon.
2. Balance hydrogen.
3. Balance Oxygen. (if there is an even number of oxygen on the reactant side and odd on the product side, double the coefficient of all but O2 before balancing oxygen.)
What is a chemical change, and how can you identify one?
A chemical change happens during a chemical reaction when one substance changes into another substance.
There are many physical signs of a chemical change happening, but a new substance forming is the key.
What is the significance of the atomic number?
Atomic number identifies an element and is equal to the protons (always) and electrons of a neutral atom.
Name the compound represented by the formula MnO.
manganese (II) oxide
How do you determine the chemical formula for any binary compound?
1. Determine if you follow ionic or covalent rules.
2. a)if ionic write subscripts after element symbol that will make a total of zero charge.
b)if covalent, write subscripts after element symbol that match Greek prefixes.
Give an example of a double replacement reaction.
There are hundreds of possibilities. Formulas must be accurate and partners must be swapped.
Balance the equation: C3H8 + O2 → CO2 + H2O
C3H8 + 5O2 → 3CO2 + 4H2O