4. VSEPR theory is a theory of repulsion that describes the geometry of the molecule. According to that theory, molecules take a shape, which has the minimum repulsion between outer shell electrons (bonds). In other words, the bonds try to be as far away from each other as geometrically possible.
In VSEPR, single and double bonds are considered equivalent in terms of repulsions.
For the cysteine molecule below
  ![](http://stemco.org/wp-content/uploads/2023/10/Screenshot_47-300x143.png)
What are approximate bond angles x and y?Deselect Answer
4 out of 5
5. Nixtamalization refers to the process of treating maize before it is ground into flour, in order to remove mycotoxins and to increase the nutritional value of the maize. In nixtamalization, maize is cooked and soaked in an alkaline (basic) solution.
In the Americas, where maize has been a staple food for thousands of years, nixtamalization can be
traditionally conducted as such: A special type of rock is heated to high temperatures, before being
added to water. Maize is soaked and boiled in this water, before it is ground into flour.
What could be the main constituent of this special rock?Deselect Answer
5 out of 5