Unit 1 matter and radioactivity test Flashcards
how to calculate atomic mass?
do the atomic mass (isotope) times the percent and add each one to find the average.
what did soddy do?
he invented the word isotope
Which elements form diatomic particles?
Hydrogen, Oxygen,Nitrogen, Bromine, Iodine, Chlorine, Flourine
what is fusion and why does it happen?
when two small nuclei collide at a very high speed, forming one larger nuclei.
Why is not all matter conserved in the fusion process?
Some of the matter turns into photons (particle of electromagnetic radiation) or energy
What elements do fusion most regularily happen in?
The light (weight) elements (hydrogen, helium, and lithium)
what happens in positron decay and what is its symbol??
Positron decay is when an atom of an element loses a proton which becomes a neutron. one electron is gained. the symbol for positron is B+ (beta plus)
what happens in beta decay and what is its symbol?
beta decay is when a neutron becomes a proton, the symbol is B- (beta minus) and the beta particle is 0e-1 which is an electron from the nucleus.
radioactive
will spontaneously emit a particle to become stable.
what is the alpha particle?
He4 (2 neutrons and 2 protons) but atomic mass is 4 and number of protons is 2.
what is gamma decay?
does not change the isotope or element, just a slight mass loss because of energy or e=mcsquared.
why is gamma decay the most dangerous
Because of such a small mass (practically none) and such high energy (it is a particle of light) because that allows it to travel through most forms of matter, the particles are not stopped except with thick lead, particles are NOT deflected by your skin, and particles crash into your DNA and disrupt your system. Alpha and Beta particles are less dangerous because they are deflected by most solid matter and clothing.
what is fission?
fission is is when a large nuclei splits into two smaller nuclei, energy is released because it is no longer needed to connect the two nuclei. “Generates electricity for nuclear power plants”.
how is the average atomic mass calculated?
by averaging all of the stable isotopes of an element, for hydrogen it is protium (1 proton) and deutrium (1 proton and 1 neutron) or “long lived isotopes”.
what is the atomic mass on the periodic table of an element like polonium that has no stable isotopes?
the atomic mass on the periodic table is the atomic mass (number of protons) of the longest lived isotope.
