<h2>Answer : Option C) Joseph is observing the color of the reaction mixture to see whether proteins are present in the given solution.</h2><h3>Explanation :</h3>
An example of qualitative observation is the one where one uses the five senses to identify the changes in the reaction.
Here, when Joseph is studying a reaction mixture he is trying to observe a color change which will confirm that there is proteins present in the reaction mixture or not If there is a color change observed then it will confirm the presence of proteins.
Usually qualitative observations are those which can be easily predicted by using five senses.
The method of separating mixtures by means of their differences in the chemical properties of the components is less convenient because these methods requires reactions therefore needs energy, increasing the costs for the process.
Answer:
half-life of 5,700 ± 40 years
Explanation:
The maximum number of covalent bonds formed by a single carbon atom is 4
Physical chemistry is the area that deals with the
mechanisms, the rate, and the energy transfer that occurs when matter undergoes
a change. So the correct option for the given question is option “B”. Whenever
there is a change in the state of matter, the physical properties definitely
undergo a change. A solid matter will always have a definite shape and volume,
while a liquid has a definite volume but no shape. Gases do not have either definite
volume or shape. Chemical properties might not be affected, but physical
properties are definitely impacted when a matter undergoes change.
