Bromine exists as a mix of bromine 79 and bromine 81 isotopes. an atom of bromine 79 contains:
35 prot.44.neutr.35 electrons
35 prot.and 35 electrons only
44 prot.44 elect and 35 neutr.
35 prot.79 neutr. and 35 electrons
79 protons 79 electrons and 35 neutr.
which is correct please thanks Andy
SCIENCE/CHEM - DrBob222, Wednesday, May 12, 2010 at 9:41pm
# protons = atomic number. Look it up on the periodic table.
#protons + #neutrons = mass number (in this case 81 or 79)
SCIENCE/CHEM - Andy, Wednesday, May 12, 2010 at 10:01pm
does that narrow it down to 35 prot,79 neutrons and 35 electrons?
Soory bit lost on electrons...
why was there two choices for mass number???
SCIENCE/CHEM - Andy, Wednesday, May 12, 2010 at 10:32pm
aha....# of prot and electrons =35 same as atomic number.
#of neutons=mass number - atomic number=44 neutrons...
so 35 protons,44 neutrons and 35 electrons .....hows that???
SCIENCE/CHEM - DrBob222, Wednesday, May 12, 2010 at 10:52pm
very good. Why are there two mass numbers? Because the problem tells you Br comes in two flavors; i.e., mass number 79 and 81. But they only asked about the 79 isotope.
SCIENCE/CHEM - andy, Thursday, May 13, 2010 at 7:04pm