1. Write a balanced equation for the: a. alpha decay of lead-210

b. beta decay of chromium-55

c. capture of an electron by bromine-76

210 82Pb> 206 80Hg + 4 2 He

55 24 Cr>55 25 Mn + 0 -1 e

76 35 Br + 0 -1 e> 76 34 Se

Explanation:

Alpha decay occurs with atoms having high atomic number number. As the atomic number increases, the repulsions between the protons make the nucleus unstable. A point is reached where the attractive forces in the nucleus are unable to hold the nucleons together anymore. Part of the nucleus now breaks off as an alpha particle or a helium nucleus.

Beta decay involves the transformation of a neutron to a proton, electron and neutrino. It decreases the neutron-proton ratio.

The capture of an orbital electron converts a proton into a neutron with the emission of a neutrino. The atomic number of the product nucleus decreases. Orbital electron capture increases the neutron-proton ratio.

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.