Answer:
2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost.
Explanation:
"Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation."
Which statements correctly defend or dispute his conclusion?
A.)He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
B.)He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
D.)He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
Answer:
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Explanation:
From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.
Physical changes are changes that alters the physical properties of matter particularly the form and state.
Chemical changes leads to the formation of a new kind of matter.
We can see that since the salt was obtained back after evaporation, no change has occurred to it.
Therefore, evaporation in itself is a physical change process.
Answer:
c on ed
Explanation:
Which of the following molecules is most likely an enzyme?
water
glucose
protease
monosaccharide
Answer:
protease is an enzyme
Explanation:
It hydrolyse peptide bonds of proteins and also called proteolytic enzymes.