In conduction, the thermal energy of a particle is transferred to other particles throughout the solid. The particles with more energy are transferred to those with less.
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>
Answer:
The system shifts forward
Explanation:
The forward reaction is favoured in order to reduce the disruption (excess heat) to the system. Position of equilibrium shifts rightwards of the equation for excess heat to be absorbed during the endothermic forward reaction
1) D. An element
2) D. Suspension
3) A. Iodine
4) A. Atoms of the same element
Answer: The correct answer is (D).
Explanation:
Space photography help astronomers:
- To visualize and observe the position and appearance of celestial objects like: path of orbiting planets ,dim stars which invisible to naked eyes ,far away galaxies etc.
- To observe any phenomena which is occurring at macro level for example: collision of steroids and meteors etc.
