Answer: C.
Explanation:
The rusting of Clara's bike in which iron changes to rust is a chemical change. In a chemical change: the process is not easily reversible.
Answer:
a, and f.
Explanation:
To be deprotonated, the conjugate acid of the base must be weaker than the acid that will react, because the reactions favor the formation of the weakest acid. The pKa value measures the strength of the acid. As higher is the pKa value, as weak is the acid. So, let's identify the conjugate acid and their pKas:
a. NaNH2 will dissociate, and NH2 will gain the proton and forms NH3 as conjugate acid. pKa = 38.0, so it happens.
b. NaOH will dissociate, and OH will gain the proton and forms H2O as conjugate acid. pKa = 14.0, so it doesn't happen.
c. NaC≡N will dissociate, and CN will gain a proton and forms HCN as conjugate acid. pKa = 9.40, so it doesn't happen.
d. NaCH2(CO)N(CH3)2 will dissociate and forms CH3(CO)N(CH3)2 as conjugate acid. pKa = -0.19, so it doesn't happen.
e. H2O must gain one proton and forms H3O+. pKa = -1.7, so it doesn't happen.
f. CH3CH2Li will dissociate, and the acid will be CH3CH3. pKa = 50, so it happens.
Answer:
Photosynthesis removes carbon from the atmosphere, and cellular respiration releases carbon back into the atmosphere.
Explanation:
The first option clearly expresses the relationship between photosynthesis and cellular respiration.
Cellular respiration releases carbon back into the atmosphere whereas photosynthesis removes the carbon from the atmosphere.
Photosynthesis is the process whereby green plants manufacture their food using carbon dioxide and water.
In cellular respiration, the product of the photosynthesis is used by organisms to produce energy.
Answer:
Density of the substance is 0.7
Explanation:
4.2/6 = 0.7
