Answer:
D) the decay rates of radioactive uranium and lead
Explanation:
As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.
Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time
So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate
now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.
so by the formula
we can find the age of the sample
Answer:
Must be put in to break the bonds in the reactants and the energy that is released upon making the bonds in the products.
Explanation:
The heat energy is absorbed to break the chemical bonds, which are responsible for the attractive interactions between atoms and molecules, and which gives stability to chemical compounds. While the heat energy is released upon making the bonds in the chemical compounds.
Answer:
Conductors:Aluminum, copper, car cables
Insulator: rubber, glass
The following lists of
stars in order from least density to greatest density are giant, main sequence
star, white dwarf, neutron star. The answer is letter B. Aside from neutron
star being the densest star, it is also the smallest star compared to the giant
star, as its name implied.