Explanation:
A physical change is one that alters the physical properties of matter (particularly the form and state).
A chemical change is one in which new kind of matter is formed. It is always accompanied by energy changes (evolution or absorption of energy in form of heat or light or both).
Now, the salient differences between physical and chemical changes;
- Physical changes are easily reversible whereas chemical changes are not easily reversible.
- Physical changes lead to the production of no new kinds of matter whereas chemical changes leads to the production of new kinds of matter.
- Physical changes involves no change in mass whereas chemical changes involves change in mass.
- Physical changes require little energy whereas considerable amount of energy is needed for chemical changes.
Answer:
Absorbed, endothermic
Explanation:
Based on the heat of reaction, chemical reactions may be classified as endothermic or exothermic.
In an endothermic reaction, heat is absorbed from the surrounding. As heat is absorbed from the surrounding, the reaction vessel feels cool when touched.
On the other hand, in an exothermic reaction, heat is given out by the system to the surrounding and the reaction vessel feels hot when touched.
Hence the reaction is endothermic and energy is absorbed during the reaction.
Both are mainly composed of droplets of condensed water
Answer:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
Explanation:
Answer:
oxidation state of sulphur=x
Explanation:
Na2S4O6=2[+1]+4x+6[-2]=0
+2+4x-12=0
4x-10=0
4x=10
x=10/4=2.5