Explanation:
A chemical reaction is defined as the reaction in which bonds between the reactants either break or form which leads to the formation of a new substance.
For example, 
So, when we drop a sodium metal into water then it produces a frizzing sound which shows the metal is reacting with water.
We know that when two aqueous solutions chemically react with each other then it may lead to the formation of an insoluble substance which is known as precipitate.
This means that formation of a precipitate is also a chemical reaction.
Thus, we can conclude that following are the statements which show evidence for a chemical reaction.
- Dropping sodium metal into water produces fizzing.
- Mixing two aqueous solutions produces a precipitate.
Answer:
N2 + 3H2 + 2NH3
Explanation:
I'm assuming you're balancing the chemical equation
Option a: alkene
Styren is C6H5CH=CH2, i.e. ethenylbenzene
The rate<span> of a </span>reaction increases<span> if the temperature is increased, the concentration of a dissolved reactant is increased and the pressure of a </span>reacting<span> gas is increased. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
Air is an example of a solution. The other two answers are incorrect because they are heterogenous mixtures, not homogenous mixtures(another name for solution).