1. Americium - 243 emits an alpha particle. What would its new atomic number and identity be? *

92, uranium

90, Thorium

93, Neptunium

97, Berkelium

2. Lead - 206 emits gamma radiation. What is the change in atomic number? decreases by 2

decreases by 1

remains the same

increases by one

3. In transmutation it is possible for a neutron to break down and form

an alpha particle

a proton and an electron

a helium nucleus

2 protons

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.