Chemical change<span> is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. These changes are chemical:</span>
<span>iron rusting (iron oxide forms)gasoline burning (water vapor and carbon dioxide form)eggs cooking (fluid protein molecules uncoil and crosslink to form a network)bread rising (yeast converts carbohydrates into carbon dioxide gas)milk souring (sour-tasting lactic acid is produced)suntanning (vitamin D and melanin is produced)</span>
Physical change rearranges molecules but doesn't affect their internal structures. Some examples of physical change are:
<span>whipping egg whites (air is forced into the fluid, but no new substance is produced)magnetizing a compass needle (there is realignment of groups ("domains") of iron atoms, but no real change within the iron atoms themselves).<span>boiling water (water molecules are forced away from each other when the liquid changes to vapor, but the molecules are still H2O.)</span>dissolving sugar in water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.)dicing potatoes (cutting usually separates molecules without changing them.)</span>
Classification of real processes can be tricky. Complex changes can be broken down into many simpler steps. Some of the steps are chemical and others are physical, so the overall process can't cleanly be placed in either category. For example, boiling coffee involves chemical change (the delicate molecules that give coffee its flavor react with air and become new, bitter-tasting substances) and physical change (the water in the coffee is going from liquid to gaseous form.)
Answer:
1) False
2) there are equal amounts of rectants and products
Explanation:
1) When dynamic equilibrium is achieved. the rate of forward and backward reaction they are the same, that is to say, two opposite reactions occur at the same rate, keeping the concentrations constant over time. Different to say the rate of the ractions go to zero.
2) A chemical equilibium exists when what is produce in quantities is equal to what reacts.
So the correct answer is the literal (d).
Answer:
The given molecules are SO2 and BrF5.
Explanation:
Consider the molecule SO2:
The central atom is S.
The number of domains on S in this molecule is three.
Domain geometry is trigonal planar.
But there is a lone pair on the central atom.
So, according to VSEPR theory,
the molecular geometry becomes bent or V-shape.
Hybridization on the central atom is
.
Consider the molecule BrF5:
The central atom is Br.
The number of domains on the central atom is six.
Domain geometry is octahedral.
But the central atom has a lone pair of electrons.
So, the molecular geometry becomes square pyramidal.
The hybridization of the central atom is 
.
The shapes of SO2 and BrF5 are shown below:
Level 3 is the correct answer
Answer : The balanced reduction half-reaction is:
Explanation :
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
The given balanced redox reaction is :
The half oxidation-reduction reactions are:
Oxidation reaction : 
Reduction reaction : 
In order to balance the electrons, we multiply the oxidation reaction by 2 and reduction reaction by 3 and then added both equation, we get the balanced redox reaction.
Oxidation reaction : 
Reduction reaction :
The balanced redox reaction will be:
Thus, the balanced reduction half-reaction is:
