Answer:
Ionic substance
Explanation:
An ionic substance is formed when oppositely charged ions link up to form an infinitely large lattice structure that can only be described in terms of unit cells.
Ionic substances may consist of billions of oppositely charged ions. Ionic substances are hard, have high melting and boiling points and do not conduct electricity in the solid state because the ions are not free in the solid state.
However, in solution or molten state, the substance conducts electricity since the ions which are the charge carriers are now mobile.
Answer:k
Explanation:
Atomic theory would be the theory or explanation of the function of atoms and their relationship with each other.
To do this problem it is necessary to take into account that the heat given by the unknown substance is equal to the heat absorbed by the water, but considering the correct sign:

Clearing the specific heat of the unknown substance:

After 2 half-lives there will be 25% (1/4th) of the original isotope, and 75% (3/4 th) of the decay product
<h3>What is Half life period ?</h3>
A half life is a measurement of the slope of an exponential decay function.
It is also defined as, the time it takes to halve the concentration of something in a process.
Each half life you will have half of what you had at the beginning of a given half life.
Learn more about half life here ;
brainly.com/question/9654500
#SPJ1