The table describes the nuclei of four atoms:
| thorium-230 | thorium-232 | uranium-234 | neptunium-234 |
|---|---|---|---|
| 90230Th^{230}_{90}\text{Th}90230Th | 90232Th^{232}_{90}\text{Th}90232Th | 92234U^{234}_{92}\text{U}92234U | 93234Np^{234}_{93}\text{Np}93234Np |
Atoms contain electrons. Which nucleus needs the largest number of electrons to form a neutral atom?
Which two nuclei have the same number of protons?
Which two nuclei have the same number of nucleons?
Which two nuclei have the same number of neutrons?
Explain what is meant by the term unstable.
Explain what is meant by the term half-life.
When uranium-234 decays, it emits an alpha particle and a gamma ray. Complete the decay equation for uranium-234 by identifying the missing values of a,b,c,d,e, a, b, c, d, e,\,a,b,c,d,e, and f f\,f in:
92234U→baα+dcX+feγ {}^{234}_{92}\text{U} \rightarrow {}^{a}_{b}\alpha + {}^{c}_{d}\text{X} + {}^{e}_{f}\gamma 92234U→baα+dcX+feγUse information from the table to identify element X.
The nucleus of neptunium-234 can absorb an electron. When this happens, one of the protons in the nucleus becomes a neutron according to the equation:
11p+−10e→01n {}^{1}_{1}\text{p} + {}^{0}_{-1}\text{e} \rightarrow {}^{1}_{0}\text{n} 11p+−10e→01nDescribe how this process affects the proton number and the nucleon number of the nucleus that absorbs the electron.
Identify the new nucleus formed by this process.
