Answer:
carbon-12 is not radioactive
Explanation:
The measurement of the age of dead carbon based life forms requires the use of a radioactive isotope hence it is often referred to as radiocarbon dating.
Carbon-12 and Carbon-14 occur together in living things.The half life of Carbon-14 is about 5670 years.
Hence, since Carbon-12 is not radioactive, it can not be used to measure the age of dead carbon based materials.
Answer:
160.9 mol ≅ 161.0 mol.
Explanation:
- It is known that every 1.0 mole of compound or element contains Avogadro's number (6.022 x 10²³) of molecules or atoms (formula units).
Using cross multiplication:
1.0 mole of Fe(NO₃)₃ contains → 6.022 x 10²³ formula units.
??? mole of Fe(NO₃)₃ contains → 9.69 x 10²⁵ formula units.
<em>∴ The no. of moles of He contains (9.69 x 10²⁵ formula units)</em> = (1.0 mol)(9.69 x 10²⁵ formula units.)/(6.022 x 10²³ formula units) = <em>160.9 mol ≅ 161.0 mol.</em>
Answer:
Option D
Explanation:
Rutherford deduced that the atomic nucleus was positively charged because the alpha particles that he fired at the metal foils were positively charged, and like charges repel. Alpha particles consist of two protons and two neutrons, so they are positively charged. In Rutherford's experiments most of the alpha particles passed straight through the foil without being deflected. However, occasionally the alpha particles were deflected in their paths, and rarely the alpha particles were deflected backward at a 180 degree angle.
Since like charges repel, Rutherford concluded that the cause of the deflections of the positively charged alpha particles had to be something within the atom that was also positively charged. Rutherford concluded from his metal foil experiments that most of an atom is empty space with a tiny, dense, positively charged nucleus at the center that contains most of the mass of the atom.
