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>
Hello!
The fission of an atom that has a large atomic number can be induced by bombarding the atom with neutrons.
Nuclear fission occurs when a heavy nucleus divides into two or more lighter nuclei. This reaction is induced by the bombarding of neutrons into the nucleus, making it unstable (like throwing an orange to a perfectly arranged orange pyramid at the supermarket). The unstable nucleus breaks down into lighter elements, releasing more neutrons which contribute to the chain reaction.
Have a nice day!
<h2>Complete the table to summarize the properties of the different subatomic particles. </h2>
Explanation:
Atom
It is a smallest particle which cant exist independently.
According To Dalton, atom was indivisible but later on, it was proved that atom can be subdivided into sub atomic particles called electron, proton & neutron.
These subatomic particles have marked properties .
Proton
- It was discovered by E.Goldstein .
- It is positively charged particle
- It is present in nucleus .
- Its mass is equal to 1.6726219 × 10⁻²⁷ kilograms
Neutron
- It was discovered by E.chadwick .
- It is neutral
- It is present inside the nucleus .
- It's mass is equal to 1.674927471×10⁻²⁷ kg
Electron
- It was discovered by J.J Thomson .
- It has negative charge .
- It's mass is equal to 9.10938356 × 10⁻³¹ kilograms
- It is present outside the nucleus in shells .
A cloud that forms on the ground is called fog. Some clouds you see in the sky might be from airplanes. These are called contrails. High level cirrus clouds may travel at speeds up to 100 mph.
yes
Explanation:
the molar mass of a compound is g/mol
