In order to digest food, the human body requires a. high activity to burn off energy. b. physical reactions in the stomach lining. c. sleep to perform the necessary break down of molecules in food. d. enzyme catalysts to speed up reactions.

D. enzyme catalysts to speed up reactions

Explanation:

In order to digest food, the human body requires enzyme catalysts to speed up reactions. The digestion process starts from the mouth, to the stomach to the small intestines. In the mouth, we chew the food and mixes it with the saliva which contains salivary amylase. In the stomach, pepsin is the enzyme present. It digest proteins and nutrients from foods are sent to the different parts of the body that needs it.

D. Enzyme catalysts to speed up reactioins

Explanation:

just took the test :)

the movie was based there, and all the animals and characters are native.

~courtney

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.