After two half life it must be 1200 x 1/2 x 1/2 = 300 atoms.
All of the actinides are radioactive, and almost all are synthetic.
Group 3 of the periodic table contains many of the radioactive elements.
A radioactive rock is one which contains traces of radioactive isotopes. These isotopes release radiation in its various forms. Any rock can be radioactive, but in particular igneous rocks tend to have radioactive properties. This is because they may have radon gas trapped in their crystals, which, under pressure, is released (this is why radon gas is used as an indicator of an upcoming earthquake). Radon gas is radioactive, and this causes the rock to be radioactive also.
Yes. A radioactive atom is a radioactive atom. If that atom exists as a single atom and is uncombined and it is radioactive, it's radioactive. If that same atom is chemically combined with another or other atoms, it's still radioactive. It's just that simple.
True. Our body naturally contains several radioactive isotopes such as potassium-40, carbon-14, and radon-222. These isotopes are present in very small amounts and are generally not harmful to health.
The most familiar of the radioactive minerals is pitchblende which contains uranium.
true
All of the actinides are radioactive, and almost all are synthetic.
Salt substitute - contains potassium chloride. A slight amount of naturally occuring potassium is radioactive.
Any of a variety of elements might do for this, including thorium and uranium, but even potassium has an important radioactive isotope in it.
Group 3 of the periodic table contains many of the radioactive elements.
A radioactive rock is one which contains traces of radioactive isotopes. These isotopes release radiation in its various forms. Any rock can be radioactive, but in particular igneous rocks tend to have radioactive properties. This is because they may have radon gas trapped in their crystals, which, under pressure, is released (this is why radon gas is used as an indicator of an upcoming earthquake). Radon gas is radioactive, and this causes the rock to be radioactive also.
It contains a higher amount of radioactivity
Yes. A radioactive atom is a radioactive atom. If that atom exists as a single atom and is uncombined and it is radioactive, it's radioactive. If that same atom is chemically combined with another or other atoms, it's still radioactive. It's just that simple.
tRNA contains the anticodon
The actinoids (formerly actinides) are all unstable metallic elements. The period 7 elements with atomic numbers from 89 (actinium, for which the group is named) through 103 comprise these elements. A link can be found below.
Oh, but they are. An alpha particle contains two protons.