Hello
What do u need help with
Answer:
The open system evaporates the solvent in the solution
Explanation:
An open system is a system in which exchange of materials and energy can occur. If a TLC set up is left open, then the set up constitutes an open system.
During TLC, the sample is dotted on the plate and inserted into a suitable solvent. The solvent moves up the plate and achieves the required separation of the mixture.
Most of these solvents used used TLC are volatile organic compounds. Therefore, if the TLC set up is left open, the solvent will evaporate leading to poor results after running the TLC experiment.
Answer:
Column 17 halogens
Explanation:
To answer the question we need to know the following;
What are valence electrons?
- Valence electrons are outermost electrons in the outermost energy level of an atom of any element.
What are halogens?
- Halogens are group 7 elements that have seven valence electrons. They include, chlorine, fluorine, iodine, etc
What is the reactivity of halogens?
- Halogens are the most reactive non-metals in the periodic table. They react by gaining one electron to attain a stable configuration.
Answer:
Splitting water molecules produces hydrogen gas, which is used to power machines through hydrogen fuel cells. ( B-)
Distance and period of time is the correct answer
Hope this helps!