Answer:
We are asked to describe the half-life of the radioactive materials.
- Hence the 3rd option is correct
repartExiplanation:cionde atomos
Answer:
leave little space between the molecules.
Explanation:
Matter is made up of small particles called molecules. These molecules present in matter are arranged inside its bulk.
In liquids and solids, the molecules are arranged very close together in such a way that there is only a little space between them. This is why liquids and solids are referred to as "condensed phases".
They are quite unlike gases where there is a lot of space between gas molecules.
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases.
Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
