Unit 2 chemistry

Democritus

particle theory of matter. Atom= smallest particle of an element that retains in a chemical reaction

John Dalton

sold sphere model matter is made up of indvisible atoms, which combines to form compounds. He proposed that each element is characterized by the mass of its atoms.

JJ Thompson

Plum pudding model (cathode ray tube experiment) led to disocrvy of electron

Ernest Rutherford

Nuclear model gold foil experiment

Niels Bohr

planetary model

Erwin Schrodinger

quantum model

James Chadwick

disproved the neutrons and showed it was in the nucleus

elements are made of tiny particles called…

atoms

all atoms of the same element are…

identical

charge of protons

postive

charge of neurons

neutral

charge of electrons

negative

Atoms are always

neutrons

mass number formula

protons + neurons

what order on the left is the atomic number and mass number

mass number on top and atomic on button

how to find mass number

number of neurons in nucleus

how to find atomic number

number on periodic table

what is atomic number equal to

protons and electrons

how to find average atomic mass

so for the first element take the abundance move the decibel point two to the left and multiply to the mass, do the same thing for 2nd element and add those two together

Radioactivity

spontaneous emission of radiation in form of particles or high energy photons resulting from nuclear recations

Nucular reactions

involve nucleus

chemical reactions

involve electrons

nuclear instability

occurs when an atomic nucleus has an imbalance of protons and neutrons, leading to radioactivity.

nuclear decay

the process by which an unstable atomic nucleus loses energy by emitting radiation.

Alpha decay

mass decrease by 4 and atomic decrease by 2

beta decay

mass no change atomic increase by one

how to write alpha decay

(what it was) → (what it became) + 4/2 He

how to write beta decay

(what it was) → (what it became) + 0/-1 B

Fisson

nucleus splits into smaller nuclei to become more stable

fusion

nuclei fuse into larger nucleus to become more stable

what does Mo mean?

original mass

what does n mean?

number of half lives

what does mf mean

final mass

what does t mean

time elapsed

what does t1/2 mean

half life time