Answer:
the throwing back by a body or surface of light, heat, or sound without absorbing it.
"the reflection of light"
Explanation:
i hope this helps
When a sodium atom transfers an electron to a chlorine atom, forming a sodium cation (Na+) and a chloride anion (Cl-), both ions have complete valence shells, and are energetically more stable. The reaction is extremely exothermic, producing a bright yellow light and a great deal of heat energy.
Answer: precipitation of 
from 
and 
ions in solution
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
is positive when randomness increases and is negative when randomness decreases.
a) precipitation of from and ions in solution : As ions are getting solidified, entropy decreases.
b) dissolution of 
in water: The compounds dissociates into ions, entropy increases.
c) melting solid gold into liquid gold: The randomness increases, entropy increases.
d) evaporation of Hg(l) to form Hg(g) : The randomness increases, entropy increases.
e) mixing of two gases into one container : The randomness increases, entropy increases.
The electronic configuration of a chlorine ion in BeCl2 compound is
[2.8.8]^- (answer B)
chlorine atom gain on electron form Be to form chloride ions
chlorine atom has a electronic configuration of 2.8.7 and it gains one electron to form chloride ion with 2.8.8 electronic configuration
