<u>Answer:</u>
<em>1) ∆H is positive
Endothermic
</em>
<em>2)
Endothermic </em>
<em>3) Energy is absorbed
Endothermic
</em>
<em>4)
Exothermic
</em>
<em>5) ∆H is negtive
Exothermic
</em>
<em></em>
<u>Explanation:</u>
∆H is called as enthalpy change
It is also called as Heat of reaction
Energy is required for the bond to break a bond.
Energy is released when a bond is formed.

that is

We see in this equation, bonds between hydrogen and chlorine molecules gets broken and on the right side bond is formed in HCl.
If energy of products greater than energy of reactants then the reaction enthalpy change is endothermic .
If energy of products lesser than energy of reactants then the reaction enthalpy change is exothermic .
For example



(positive hence endothermic)



(negative hence exothermic)
Answer:
isotope 2
Explanation:
it has the highest percentage abundance
A physical property of an element is a property of an element that can observed or measured without changing the chemical nature of the element.
A chemical property of an element is a property of an element that can only be observed or measure when the chemical property of the element is altered or changed.
Based on this;
The boiling point of bromine is a physical property of bromine.
The high reactivity of bromine with many elements is a chemical property of bromine.
Answer:
Odour is intensive
Explanation:
intensive properties are Independent of the amount of matter