The half-life of potassium-40 is about 1.25x10^9, or 1.25 billion, years. it undergoes beta decay and becomes argon-40. Equal amounts would be one half-life, so the sample is also 1.25x10^9 years old.
Answer:
Today, the atom is defined as the smallest particle that can be considered an element.
Explanation:
Answer:
The equation that correctly describes the decay is :
Ra -----> Rn + He
Explanation:
When the solid radium start decaying in order to form the radon gas, it starts losing two protons with one neutron. The two neutron as well as one proton together forms an alpha particle, hence a type of radiation is formed. Also we know that radon itself is radioactive as it also leads to the decay, after that it loses an alpha particle and also form an element called as polonium. Radium being the most stable form of isotope, radium 226, also holds a half life of 1600 years. It will decay into radon 222 through the alpha decay or can also lead 212 by ejecting a carbon 14 nucleus.
Given question is incomplete. The complete question is as follows.
The successive ionization energies of a certain third-period element are I1 = 577.9KJ/mol, I2 + 1820 KJ/mol, I3 = 2750 KJ/mol, I4 = 11600 KJ/mol, I5 = 14800 KJ/mol. what element do these ionization energies suggest? Explain your reasoning.
Explanation:
Ionization energy is defined as the energy required to remove the most loosely bound electron from a neutral gaseous atom.
Here, given ionization energies belong to an element present in third period.
We know that second ionization energy will always be greater than third ionization energy.
For the given ionization energies, there is a huge difference between third and fourth ionization energy. This means that there are three valence electrons present in the element.
This is because after losing three electrons it is difficult for the given element to lose fourth electron. Hence, is high as compared to .
Hence, this element has 3 valence electrons and it belongs to 3A group of the periodic table.
Thus, we can conclude that the given unknown element is aluminium (Al).