Answer:
Henry Moseley
Explanation:
Dmitry Mendeleef and Lothar Meyer proposed a periodic table based on the atomic mass.
They stated a periodic law expressed as "chemical properties of elements are a periodic function of their atomic weights".
But, Henry Moseley in 1900s re-stated periodic law by changing the basis of the law from atomic weight to atomic number.
The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".
<h2>The required option d) "specific heat" is correct.</h2>
Explanation:
- To raise the temperature of any substance or material of certain mass to respective temperature it requires some amount of heat.
- Specific heat is the amount of heat necessary to raise the temperature of the substance of 1 gram to 1 Kelvin.
- It is the amount of heat which is required to raise the temperature per unit mass to per unit temperature.
- Thus, the required "option d) specific heat" is correct.
Pb (lead) is in the 6th period
(please give brainliest if this helped you)
Answer:
I don't know if this will help but. The Great Sphinx has suffered from erosion and vandalism. Hatshepsut's stepson was too young to rule at the time of her husband's death, so she just took the job.
Magic number is any number in electron shells that suggest stability. It corresponds to total number of electrons in filled electron shells.
If an electron is having magic number, then it forms stable bonds.
Explanation:
The magic numbers are 2,10,18,36,54, 86 and 126. This refers to the total number of electrons that an electron can have when it is completely filled.
Atomic nuclei which carries either of these nucleons have high binding energy as compared to others. Hence, they have high stability. Bonds in such elements are more strong.
Radioactive decay of such elements is very slow.
Eugene Winger coined the term "magic number".
