last minute midterm

Dalton’s atomic theory - 1

matter is composed of atoms and atoms are the smallest unit of an element that can participate in chemical change

Dalton’s atomic theory - 2

each element consists of one type of atom with a consistent mass

Dalton’s atomic theory - 3

atoms of one element differ from properties of all other elements

Dalton’s atomic theory - 4

a compound consists of two or more elements combined in a small whole number ratio

Dalton’s atomic theory- 5

atoms are neither created nor destroyed during a chemical change but are instead rearranged to yield substances that are different from those present before the change

law of definite proportions

all samples of a pure compound contain the same elements in the same proportion by mass

law of multiple proportions

when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers

an election is __ charged

negatively

a proton is ____ charged

positively

isotopes are __

atoms of the same element that differ in mass

neutrons are ___

uncharged subatomic particles with the same mass as protons

how to determine the number of protons

atomic number

how to calculate the number of neutrons

the mass number minus the atomic number

how to calculate ionic charge

protons minus electrons

how to calculate average atomic mass

divide percentage abundance forms by 100

abundance = %/100

calculate the mass contribution of each isotope

Multiply the decimal abundance of each isotope by its given atomic mass.

contribution = abundance x mass