Answer:
C
Explanation:
A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.
A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.
Answer:
A communicable disease
Explanation:
Diseases that can be transferred are known as communicable diseases.
I believe D. because all the organisms that live in a lake can be a bunch of living things that would be considered a population and not a species. I canceled out B. from the get go because, I don’t believe non living organisms can be in a population ?
Please get back to me if I’m right or wrong :)
Answer:
89.4%
Explanation:
Initially, there is 5.0 of the acetanilide in 100 mL of water, then the solution is chilled at 0ºC. The solubility represents the amount that the solvent (water) can dissolve of the solute (acetanilide). So, at 0ºC, 100 mL of water can dissolve till 0.53 g of the compound, the rest will precipitate and will be recovered.
So, the mass that is recovered is 5.0 - 0.53 = 4.47 g
The percent recovery is:
(4.47/5)x100% = 89.4%
Answer:
moon, planet, sun, solar system, galaxy, Universe
Explanation:
I am not fully sure but I think this is right
but I apologize if it is wrong