Gain 1.
This is because of Chlorine's placement on the periodic table. Chlorine is a Halogen, thus being located in group 17 or 7A. This means it is one of the closest elements to being a Noble Gas or group 18/8A.
Chlorine has 7 valence electrons, and in order for it to become a Noble Gas, it needs 8. Cl- is typically the symbol used to represent this as Chlorine needs to gain an electrons instead of lose; once Chlorine gains the electron, it will be stable.
This also means that Chlorine has a high ionization energy or, in simpler terms, it would be difficult to remove an electron from Chlorine.
Hope this helps!
Increasing temperatures in a reaction increases the kinetic energy of the reactant molecules. This causes them to move fast and hence collide with a higher frequency. The higher the rate of collision between the molecules, the faster the reaction.
Explanation:
I can't guess it properly
Answer: Alkali metals, group 1
Explanation: Group 1 means 1 valence electron. This group is called alkali metals, which indicates that it is a metal. They are highly reactive because only 1 electron needs to move to bond with something (since it only has 1 valence electron)
