Answer:
2S02 + O2 ---> 2SO3
<u><em>Its</em><em> </em><em>balanced</em><em> </em><em>now</em><em> </em><em>as</em><em> </em><em>Reactants</em><em> </em><em>=</em><em> </em><em>Products</em><em>.</em><em> </em></u>
1) Answer: A hot pack feels warm when chemicals in it combine.
Explanation: Reactions or process in which heat is released(produced) are known as exothermic reactions or process and those in which the heat is absorbed are known as endothermic reactions or process.
If a beaker feels cools when chemical in it react then it means the chemicals have absorbed the heat energy from its surroundings and so it is an example of an endothermic process.
A hot pack feels warm when chemicals in it combine means the energy is released in the chemical reaction and so it is an example of an exothermic process.
Plants use the sun's energy for photosynthesis which is a process of forming food for the plants. Energy acts as a reactant in this process and so it is an example of endothermic process.
Frying an egg by heating it on a stove is an example of an endothermic process as the heat is required to fry the egg.
So, the only exothermic process is the second one, "A hot pack feels warm when chemicals in it combine."
2) In the given equation, heat is written as a product means the heat is released in the equation and so it is an example of an exothermic reaction.
So, the correct choice is the last one " It is exothermic because energy is released."
Answer:
A process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.
Explanation:
Pretty much just not a physical reaction or otherwise
Answer: The black ball will have more mass than the white ball.
Explanation: Density of a substance is defined as the ratio of mass and volume occupied by the substance.
Mathematically,
We are given that the two balls are of same size, which means that the volume of both the balls are same. We are also given that the black ball is more dense than the white ball, which means that the black ball will have more mass.
As, 
Answer:
the abbreviation form of full name is called symbol.
the smallest unit of cimpound is called molecule.
