Module 4 DBA notes
A physical change is one that affects only the physical properties of a substance, while a chemical change alters a substance at the molecular level.
Physical Properties: A property that can be observed or measured without changing the chemical identity of the substance.
Physical properties can be categorized as either intensive or extensive.
Reactivity:
An element or compound’s reactivity is its ability or capacity to react, or bond, with another substance. As you continue through this course, you will observe and compare this particular chemical property in a variety of scenarios.
Flammability:
One type of chemical reaction, called combustion, involves the burning of various compounds and elements. Some substances are more combustible, or able to be burned, than other substances.
Oxidation state:
The difference in the number of electrons associated with an atom as a pure element as compared with that atom in a compound. An element’s electronegativity value and other properties affect its oxidation state in different compounds.
Decomposition:
Some compounds decompose into more than one different element or compound as bonds are broken. Hydrogen peroxide (H2O2), a chemical you may have around your house, is stored in a dark container to slow down decomposition, which can be caused by heat and light.
clues that can indicate that a chemical change has occurred include: production of flames, color change, bubbling or fizzing, smoke, production of heat or light, and formation of a substance in a different state (for example, a solid from the mixing of two liquids)
Chemical equations: a representation, using formulas and symbols, of a chemical reaction.
Reactants: The substances that are present at the beginning and undergo a chemical reaction.
Products: The new substances that are formed or produced by a chemical reaction.
(reactantsproducts)
-(aq) for aqueous solution
Law of Conservation of Mass: Matter is neither created nor destroyed during an ordinary
Physical Properties: A property that can be observed or measured without changing the chemical identity of the substance.
Physical properties can be categorized as either intensive or extensive.
Reactivity:
An element or compound’s reactivity is its ability or capacity to react, or bond, with another substance. As you continue through this course, you will observe and compare this particular chemical property in a variety of scenarios.
Flammability:
One type of chemical reaction, called combustion, involves the burning of various compounds and elements. Some substances are more combustible, or able to be burned, than other substances.
Oxidation state:
The difference in the number of electrons associated with an atom as a pure element as compared with that atom in a compound. An element’s electronegativity value and other properties affect its oxidation state in different compounds.
Decomposition:
Some compounds decompose into more than one different element or compound as bonds are broken. Hydrogen peroxide (H2O2), a chemical you may have around your house, is stored in a dark container to slow down decomposition, which can be caused by heat and light.
clues that can indicate that a chemical change has occurred include: production of flames, color change, bubbling or fizzing, smoke, production of heat or light, and formation of a substance in a different state (for example, a solid from the mixing of two liquids)
Chemical equations: a representation, using formulas and symbols, of a chemical reaction.
Reactants: The substances that are present at the beginning and undergo a chemical reaction.
Products: The new substances that are formed or produced by a chemical reaction.
(reactantsproducts)
-(aq) for aqueous solution
Law of Conservation of Mass: Matter is neither created nor destroyed during an ordinary