Answer:
a. absorbs energy as heat and has positive enthalpy of solution.
Explanation:
A reaction can either be exothermic or endothermic. An endothermic reaction, as the dissolution described in the question, is that which absorbs heat energy from the surroundings in order to start the reaction.
Because an endothermic reaction makes heat lost from the surroundings, the enthalpy (∆H) of the solution will be positive (+). ∆H is got by finding the difference between the enthalpy of the reactants and products and since the enthalpy of a product in endothermic reaction is more, the enthalpy change (∆T) will be positive.
Answer:
hahah animals in the world
We can define atomic mass the total of number of protons and number of neutrons in an atom or isotope.
<span>So when an isotope of yttrium has 39 protons and 59 neutrons, its atomic mass is equal to;
number of protons + number of neutrons = 39 + 59 = 98</span>
