Answer:
Lactose is found in animal milk is lactase is the enzyme that is required to digest it.
Explanation:
Lactose is a disaccharide made of glucose and galactose units. This sugar is naturally present in animal milk and it is digested (broken in its units) by the lactase enzyme.
Some people are lactose intolerant because their bodies is not able to produce the enzyme. If they ingest dairy products it may cause health issues. Nowadays it is possible to purchase the lactase enzyme and ingest it with a dairy food to avoid any health effects.
Answer:
The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.
Explanation:
The energy of nth energy levels of the H atom is given as:

Energy of the seventh energy level = 


Energy of the seventh energy level = 


Energy of the light emitted will be equal to the energy difference of the both levels.


Wavelength corresponding to energy E can be calculated by using Planck's equation:


The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.
Answer:
A.evidence to the existence of life
Explanation:
1) Convert 12.9 liters of Oxygen to mol at the given conditions:
PV = nRT ⇒ n = PV/RT
n = [1.2atm*12.9 l] / [0.082 atm l /K mol * 297K]
n = 0.636 mol of O2
2) use the stoichiometry derived from the balanced chemical equation
1mol C2H4 / 3 mol O2 = x mol C2H4 / 0.636 mol O2
x = 0.636 / 3 mol O2 = 0.212 mol O2.
Answer: 0.212 mol O2
Answer:
Addition of a catalyst can speed up a reaction by providing an alternate reaction pathway that has a lower activation energy
Explanation:
A catalyst is an agent that increases the rate of a chemical reaction by providing an alternate pathway for the reaction that requires a lower activation energy. As the requirement for activation energy is less in the presence of a catalyst, there are more reactant particles becoming involved in the chemical reaction and as such there are more products formed per unit time, or there is an increase in the rate of the reaction
Example of catalyst include
1. Addition of potassium permanganate to hydrogen peroxide to aid in the rapid decomposition into water and oxygen
2. Platinum serves as a catalyst in the complete combustion of carbon monoxide into carbon dioxide.