<span>37.9968064 ± 0.0000010 g/mol</span>
Answer:
100 grams of C-14 decays to 25 grams in 11,460 years.
The C-14 isotope is only useful for dating fossils up to about 50,000 years old
If an ancient bone contains 6.25% of its original carbon, then the bone must be 22,920 years old.
Explanation:
We already know that the half life of C-14 is 5,730 years. After the first half life, we have 50 grams remaining. This takes 5,730 years. After the second half life (11,460 years now gone) we have 25 grams of C-14 left.
If a fossil material is older than 50,000 years an undetectable amount of 14C is left in the sample hence Carbon-14 is no longer suitable for dating the sample.
From;
0.693/5730 = 2.303/t log (No/0.0625No)
Where;
t = time taken and No = initial amount of C-14
0.693/5730= 2.77/t
t = 22,920 years
In a permanent magnet, a magnetic field is produced by the composite motions of electrons in geometrically aligned atoms.
A magnetic field is characterized by poles called north and south. Magnetic polarity refers to the orientation of these poles in space.
Atoms are electrically neutral because the number of protons, which carry a 1+ charge, in the nucleus of an atom is equal to the number of electrons, which carry a 1- charge, in the atom. The result is that the total positive charge of the protons cancels out the total negative charge of the electrons so that the net charge of the atom is zero. Most atoms, however, can either gain or lose electrons; when they do so, the number of electrons becomes different from the number of protons in the nucleus. The resulting charged species is called an ion.
