a pure substance that cannot be broken down into other substances
measures the quantity of matter in any given object (wieght)
Protons wiegh one atomic mass unit
Neutrons weigh one atomic unit
eletrons have no mass
is the number of protons in the nucleus
Different type of atom of the same chemical element, each having a different number of neutrons
CO2 Tells two pieces of info:
Describes which types of atoms are in a molecule and how many of each
two-dimentional representations of a given molecule
Each line represents one shared pair of electrons
Covalent bonding: polar and non polar
Formed when two atoms share one or more pairs of outer-shell electrons
Nonpolar covalent bond: electrons are shared equally, charges are symmetric meaning no difference in electrical charge at one end as opposed to the other.
Polar covalent bond: has opposite charges on opposite ends, some atoms have greater electronegativity
Attraction between oppositely charged ions.
Formed when one atom gives up one or more electrons to another atom
Ion: an atom that has either a positive or negative charge, due to haveing an unequal number of protons and electrons.
weak attractions between two molecules of water in which a partially positive charged of H atoms is attracted to partially negatively charged Oxygen creating a weak attractions. Water is a polac covalent molecule
its a term to measure this kind of pull - When one atom has a greater power to attract electrons to itself than the oter atom
a difference in electrical charge at one end as opposed to the other.
Water as a good solvent
Solvent for other polar molecules
By dissolving ions and molecules, water allows chemical reactins to occur
High speacific heat: the amount of energy required to raise the temprature or a substance by 1 C.
It takes longer for water to warm up.
Ice floats because solid form of H2O is less dense, formed a maximum number of Hydrogen bonds with each other.
Cohesion: tendency of water molecules to stick together. Cohesion give water surface tension
mixture of two or more kind of molecules
what is being disolved
what disolves other substances
Acids and Bases
Whan water dissociates, it releases an equal number of hydrogen ions (H+) and hydroxide ions (OH-)
Acids: substances that release hydrogen ions in solution
Bases: substances that accept hydrogen ions or yeild hydroxide ioins in solution
pH scale: descirbes the acidity of a solution
pH stands for "potential hydrogen" or "hydrogen power"
The lower the pH, the higher the concentration of H ions
THe higher the pH, the lower the concentration of H ions
It is a logarithmic scale - pH of 2 is 10 times more acidic than pH of 3 and 100 more acidic than pH 4