An element emits one alpha particle, one positron, and three beta particles. Its atomic number....
decreases by 2
decreases by 1
stays the same
increases by 1
increases by 2
mass/atomic X ->
mass-4/atomic-2 Y + 4/2 He
mass-4/atomic-2 Y ->
mass-4/atomic+1 Y + 0/-1e +0/-1e + 0/-1e
mass-4/atomic+1 Y ->
mass-4/atomic Y + 0/+1e
To determine how the emission of particles affects the atomic number of an element, we need to understand the nature of these particles.
An alpha particle consists of two protons and two neutrons, which means it has an atomic number of 2. When an element emits an alpha particle, its atomic number decreases by 2 because it loses two protons.
A positron is a type of antimatter, which is identical to an electron but with a positive charge. It is denoted as e+. When an element emits a positron, it means it has undergone beta-plus decay, where a proton is converted into a neutron. In this process, the atomic number decreases by 1 because a proton is lost.
Beta particles are either electrons (e-) or positrons (e+). When an element emits a beta particle, it means it has undergone beta-minus decay, where a neutron is converted into a proton. In this process, the atomic number increases by 1 because a proton is gained.
Given that the element emits one alpha particle, one positron, and three beta particles, we can conclude that the atomic number decreases by 2 (from the alpha particle) and increases by 1 three times (from the beta particles).
Therefore, the total change in the atomic number is -2 + (3 * 1) = -2 + 3 = 1.
So, the correct answer is "increases by 1".