Answer:
C.3
13AL
2.8.3
The number of electrons from the outermost shell is the valence of the element.
B, because water is changing its state from solid to liquid (it's fusion in portuguese, don't know in english), so while it's changing, water has 2 states at the same time.
Answer:
A. It decreases the temperature difference between the outside and inside.
Explanation: