B .pure water it’s made up of oxygen and hydrogen “H2O”
Answer:
See Explanation
Explanation:
An endothermic reaction is one in which energy is absorbed and the change in enthalpy for the reaction is positive.
If we look at the reaction 2HgO + 45kcal ----> 2Hg + O2; we will notice that
i) 45kcal of energy was taken in (absorbed) for the reaction to occur
ii) The value of the reaction enthalpy is positive
For these two reasons, the reaction is an endothermic reaction as written.
Electron microscopes differ from light microscopes in that they produce an image of a specimen by using a beam of electrons rather than a beam of light. Electrons have much a shorter wavelength than visible light, and this allows electron microscopes to produce higher-resolution images than standard light microscopes
At one minute, a persons's heart beats 72 times.
Therefore, in one hour or 60 minutes, a person's heart will beat (60×72) times, i.e., 4320 times
Answer is 4320 times
<span>Inside the nucleus of an atom are protons and electrons. </span>
