The term half life describes the rate at which the isotopes of a particular atom decay. Thus, if you have a lump of Uranium 238 (U238), then the atoms in the lump will decay at the same rate as the half life. If that lump was created four billion years ago and it consisted of 100% U 238, today the lump would be half U238 and half something else, mostly lead. That would go for both the atoms and the whole lump.
If the lump consisted of 10% U238 today it would consist of 5% U238, and 95% something else. The fact that the U238 has a half life of 4 billion years only affects the Uranium and nothing else.
No, the half-life of each isotope can vary significantly. Different isotopes have different rates at which they decay into other elements. Some isotopes have half-lives of seconds, while others have half-lives of millions of years.
No, it changes for each one.
The correct answer is: Half-lives are not affected by temperature.
The half-life of a substance is the time taken for half of the radioactive atoms to decay. It is a fixed characteristic of each radioactive isotope. The concept of half-life is commonly used in carbon dating and nuclear medicine.
By noon, 4.5 half-lives have passed since 6:30 am (5.5 hours total). With a half-life of 110 min, fluorine-18 would have decayed 4.5 times, reducing the initial 200 mg. So, the amount of active isotope remaining would be 200 mg * (1/2)^4.5.
Bismuth has recently been found to have a no stable isotope and has a half-life of 4.6 x 10^19 years. Also, the simple hydrogen atom (a single proton), is theorized to decay at a rate of 6.6 x 10^33 years. So far all tests to observe a proton decay have failed.
An isotope of nitrogen will always have 7 protons, as this defines the element. However, it can have a different number of neutrons, thus changing the mass number of the isotope. The number of electrons in an isotope is equal to the number of protons to maintain overall charge neutrality.
the same
An isotope of a chemical element is an atom that has the same number of protons (this also means this atom has the same atomic number) and electrons, but has a different numbers on neutrons. The isotope is radioactive if it has too many neutrons in the nucleus and because of this the isotope is unstable. The half-life of a radioactive isotope is a time period. When the isotope is at the end of the period it's weight will be the half of the starter weight.
The half-life is a fixed period of time: the average time it will take for one of every two atoms to decay to another isotope or element. So no matter how much of a given radioactive isotope that you start with, only one-half of it will still be that isotope after a single half-life period. Likewise only half of that remaining material will be the same isotope after another half-life period. Of course, some of the atoms will be decaying all the time, so the half-life is only a convenient way to define the quantity at any given time.
The half-life is a fixed period of time: the average time it will take for one of every two atoms to decay to another isotope or element. So no matter how much of a given radioactive isotope that you start with, only one-half of it will still be that isotope after a single half-life period. Likewise only half of that remaining material will be the same isotope after another half-life period. Of course, some of the atoms will be decaying all the time, so the half-life is only a convenient way to define the quantity at any given time.
The correct answer is: Half-lives are not affected by temperature.
The half-life is a fixed period of time: the average time it will take for one of every two atoms to decay to another isotope or element. So no matter how much of a given radioactive isotope that you start with, only one-half of it will still be that isotope after a single half-life period. Likewise only half of that remaining material will be the same isotope after another half-life period. Of course, some of the atoms will be decaying all the time, so the half-life is only a convenient way to define the quantity at any given time.
The number of neutrons in the nucleus, the number of protons is the same for each isotope of a given element.
Because each isotope of an element has a mass different from any other isotope of the same element, and the atomic mass of an element is an average, weighted by the proportion of each isotope, in the naturally occurring element.
By noon, 4.5 half-lives have passed since 6:30 am (5.5 hours total). With a half-life of 110 min, fluorine-18 would have decayed 4.5 times, reducing the initial 200 mg. So, the amount of active isotope remaining would be 200 mg * (1/2)^4.5.
Yes, an isotope is still radioactive after one half life. There is simple one half of it left. And there will be one half of that half, i.e. one quarter left after a second half life, and half of that half, i.e. one eight left after a third half life, etc. The equation for half-life is ... AT = A0 2(-T/H) ... where A0 is the starting activity, AT is the ending activity at some time T, and H is the half-life in units of T. Sometimes, you see this equation in other forms, such as with e instead of 2, but there is another factor in the exponent. They are all the same. This equation, with the 2, makes the meaning of half-life clear because a negative power of 2 is simply 1/2, 1/4, 1/8, etc.
No....It will feel stronger and more potent, but the half life remains the same for each drug......I think?
An isotope of nitrogen will always have 7 protons, as this defines the element. However, it can have a different number of neutrons, thus changing the mass number of the isotope. The number of electrons in an isotope is equal to the number of protons to maintain overall charge neutrality.