Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>
Cause their are both have difference s
Answer:
The particle theory is used to explain the properties of solids, liquids and gases. The strength of bonds (attractive forces) between particles is different in all three states.
Explanation:
Group 6 elements usually have extra electrons to make give them an octet. So, they have 6 electrons to start and when they have an octet, they have 8.
We can find the charge by doing simple math 6 - 8 = -2
Answer is D)
Answer:
Explanation:
Replication is crucial to science. Every time researcher find something surprising that has to do with science they replicate it.
