1. Answer is 93, Neptunium.
Since this is an alpha emission the atomic number of the
daughter nucleus decreases by 2 while mass number decreases by 4 compared to
parent atom. Since parent atom, Americium has atomic number as 95, the daughter atom should have 95 - 2 =
93 as atomic number and 243- 4 =
239 as the mass number. .Due to the atomic number is 93, the daughter
element should be Neptunium.
2. Answer is "remains
the same".
Gamma radiation is also a radio-active decay and in this decay high energy
photon is emitted from an unstable high energy nucleus while becoming its low energy stable nucleus. Hence,
there is no any change of atomic number or
mass number of
the daughter element.
3. Answer is "a
proton and an electron".
Transmutation is defined as a conversion of one element into another. This
can be occurred in radioactive decays of isotopes and due to the
transmutations, the atomic number, mass number, and neutron number of the
nucleus can be changed. Due to the transmutation of β⁻ decay, a neutron can break down into a proton and an
electron.
