You can find the element with this number of protons in the periodic table. It is the element lead Pb. All types of radioactive decay pose risks to living things, but alpha decay is the least dangerous. They also are not very penetrating. However, if alpha particles are emitted inside the body, they can do more damage. One way this can happen is by inhaling cigarette smoke. People who smoke actually inhale the radioactive element polonium It undergoes alpha decay in the lungs.
Over time, exposure to alpha particles may cause lung cancer. An alpha particle consists of two protons and two neutrons, so it is actually a helium nucleus. The equation is balanced if the total numbers of protons and neutrons are the same on both sides of the arrow. At the following URL, read the article and watch the video about alpha decay. Then answer the questions below. When were alpha particles discovered, and who discovered them?
Write the nuclear equation for the alpha decay of seaborgium What element is produced in this nuclear reaction? How many neutrons does it have? Explain how to use the periodic table to identify the element produced when a given radioactive element undergoes alpha decay.
What are alpha emitters? Give some examples. If a radioactive element with 85 protons undergoes alpha decay, how many protons will there be in the new element that forms as the product of the reaction? What element is it? Fill in the missing subscript and superscript to balance the following nuclear equation. Make sure your equation is balanced. Radioactive decay of elements involving the conversion of protons or neutrons into different atomic particles.
When the nucleus of an atom decays, it becomes more stable. Atoms with unstable nuclei are radioactive. In radioactive decay, the nuclei emit energy and usually particles of matter as well. Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron.
An electron is a negatively charged particle, and a positron is a positively charged electron or anti-electron. When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay.
Beta-minus decay occurs when a nucleus has too many neutrons relative to protons , and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons , so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay?
A: Beta decay begins with a proton or neutron. You can see how in the Figure below. A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton.
In each case, the atom becomes a different element because it has a different number of protons. Radioactive nuclei and particles are represented by nuclear symbols.. For example, a beta-minus particle electron is represented by the symbol. Another example is the radioactive nucleus of thorium It is represented by the symbol , where the subscript 90 stands for the number of protons and the superscript for the number of protons plus neutrons.
This reaction is represented by the equation:. The equation shows that thorium becomes protactinium and loses a beta particle and energy. The protactinium produced in the reaction is also radioactive, so it will decay as well. A nuclear equation is balanced if the total numbers of protons and neutrons are the same on both sides of the arrow.
A: Along with another electron, it can combine with an alpha particle to form a helium atom. An alpha particle, which is emitted during alpha decay , consists of two protons and two neutrons. Q: Try to balance the following nuclear equation for beta-minus decay by filling in the missing subscript and superscript. Beta particles can travel about a meter through air.
They can pass through a sheet of paper or a layer of cloth but not through a sheet of aluminum or a few centimeters of wood. They can also penetrate the skin and damage underlying tissues. They are even more harmful if they are ingested or inhaled. The nucleus emits a beta particle and energy. A beta particle is either an electron beta-minus decay or a positron beta-plus decay. In beta-plus decay, a proton breaks down to a neutron and a positron, and the positron is emitted from the nucleus.
Read the article about beta decay at the following URL. Be sure to watch the short video at the bottom of the page. Write a balanced nuclear equation for the beta-minus decay of cesium Identify the new element that results from the reaction.
How many neutrons does this element have? What are beta emitters? It is produced from large nuclei. When an atom emits an alpha particle, the atom's mass number decreases by four due to the loss of the four nucleons in the alpha particle. The atomic number of the atom goes down by exactly two, as a result of the loss of two protons — the atom becomes a new element.
Examples of this are when uranium becomes thorium, or radium becomes radon gas due to alpha decay. Alpha particles are commonly emitted by all of the larger radioactive nuclei such as uranium, thorium, actinium, and radium, as well as the transuranic elements. Unlike other types of decay, alpha decay as a process must have a minimum-size atomic nucleus which can support it. The smallest nuclei which have to date been found to be capable of alpha emission are the lightest nuclides of tellurium element 52 , with mass numbers between and The process of emitting an alpha sometimes leaves the nucleus in an excited state, with the emission of a gamma ray removing the excess energy.
Beta Particles-. Beta emission is when a high speed electron negative charge leaves the nucleus. Beta emission occurs in elements with more neutrons than protons, so a neutron splits into a proton and an electron.
The proton stays in the nucleus and the electron is emitted.
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