<span>Balanced nuclear reaction: 234/91 Pa → 4/2 He + 230/89 Ac.
1) number of protons and neutrons on both side of nuclear reaction must be the same. There are 91 protons (atomic number) and 143 neutrons (mass number - atomic number, 234 - 91 = 143 or (4-2) + (230 - 89) = 143)) on both side of reaction.
2) a</span>lpha
decay is radioactive decay<span> in which
an atomic nucleus emits
an alpha particle (helium
nucleus) and transforms into an atom with an atomic
number that is reduced by two and mass number that is reduced by four, so atomic mass of new element is 89 (91 - 2) and mass number is 230 (234 - 4 = 230).
3) look at atomic number, element with atomic number 89 is actinium.</span>
* Answer: 448.056 meters *
——
1 yard = .9144 meters (according to Google)
100 yards= 91.44 meters
——
100*4.9= 490 yards
490 yards = 448.056 meters
* 4.9 Football fields= 448.056 meters *
I hope this helps! :)
Carbon is a non metal and also has four valence electrons.
International System of unites.