1. Isotopes with an unstable nucleus
are radioactive ***
are extremely rare
change into radioisotopes
are only found in elements with many protons
2. When Lr-256 undergoes alpha decay, it becomes
Es-252
Md-252 *** [Explanation: Lr 256 - 4 = 252, Lr 103 - 2 = 101 (Md)]
Lr-252
Md-254
3. A high-powered photon is a(n)
alpha particle
gamma particle ***
beta particle
positron
4. In a nuclear equation, a neutron can spontaneously change into a(n)
alpha particle
positron and electron
beta particle and proton ***
gamma particle
5. A radioisotope emits a beta particle. That means a(n)
neutron changed into a proton***
proton changed into a neutron
proton changed into an electron
electron got lost
Those look OK to me.
1. Answer: Isotopes with an unstable nucleus are radioactive ***
Explanation: Isotopes with an unstable nucleus are radioactive because they contain an excess of either protons or neutrons, making the nucleus unstable. In order to become more stable, these isotopes undergo radioactive decay, emitting radiation in the form of alpha particles, beta particles, or gamma rays.
To determine if an isotope is radioactive, you can look for information on its stability in a periodic table or scientific database. Isotopes that are radioactive will usually be indicated with a radioactive symbol, such as a small black triangle.
2. Answer: When Lr-256 undergoes alpha decay, it becomes Md-252 ***
Explanation: In alpha decay, an atom emits an alpha particle, which consists of two protons and two neutrons. This causes the atomic number of the parent isotope to decrease by 2 and the mass number to decrease by 4.
In this case, Lr-256 (Lawrencium-256) undergoes alpha decay to become Md-252 (Mendelevium-252). By subtracting 4 from the mass number of Lr-256 (252 = 256 - 4) and subtracting 2 from the atomic number of Lr-103 (101 = 103 - 2), we obtain the correct values for Md-252.
3. Answer: A high-powered photon is a(n) gamma particle ***
Explanation: A photon is a particle of light or electromagnetic radiation. A high-powered photon refers to a gamma particle. Gamma particles are high-energy photons, typically emitted during radioactive decay or nuclear reactions. They have no mass and carry a lot of energy, making them very penetrating and ionizing.
To identify a high-powered photon or gamma particle, you can look for its characteristics, such as having no mass and being highly energetic. Additionally, in scientific literature or databases, gamma particles are often referred to as photons with a high energy level.
4. Answer: In a nuclear equation, a neutron can spontaneously change into a(n) beta particle and proton ***
Explanation: A neutron can spontaneously change into a beta particle (electron) and proton through a process called beta decay. During beta decay, a neutron in the nucleus emits a high-energy electron and is transformed into a proton. The emitted beta particle carries away one unit of negative charge (electron) and the proton remains in the nucleus.
This transformation is represented in a nuclear equation as follows: neutron → proton + beta particle. The representation indicates that a neutron is converted into a proton while emitting a beta particle.
5. Answer: A radioisotope emits a beta particle. That means a(n) neutron changed into a proton ***
Explanation: A radioisotope emitting a beta particle means that a neutron in the nucleus of the radioisotope changes into a proton. During beta decay, a neutron decomposes in the nucleus, releasing a high-energy electron (beta particle) and transforming into a proton. The emission of the beta particle lowers the neutron-to-proton ratio in the nucleus, resulting in a more stable arrangement.
Therefore, the correct interpretation is that a radioisotope emitting a beta particle signifies a neutron changing into a proton.