The elements whose electron configurations end with f electrons are in the Lanthanide and Actinide series: those long series at the bottom of the Periodic Table (see image).
The atoms are adding electrons into f orbitals, but the f electrons are not always the last electrons in the electron configuration.
For example, the electron configuration of Eu is [Xe]6s²4f⁷, but that of Gd
is [Xe] 6s²4f⁷5d.
I have blocked off in <em>red</em> all the <em>exceptions</em> like Gd.
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.
The products. Without a balanced chemical equation, there is no reaction that can take place. The products is the final reation and the reactants help the final reaction take place.
The heavy atom count of a casein molecule is 143 I believe