Answer:
Explanation:
The octet rule does not always refer to a stable arrangement of eight valence electrons because there are some element that do not have eight valence electrons yet they are stable. for example;
i) Helium, It has two valence electrons and it is a stable gas.
ii) Boron triflouride (BF3); it has six valence electrons (deficit valence electron) yet it is also stable.
iii) Phosphorus pentachloride (PCl5); it has more than eight valence electron and it is also stable.
For these few reasons it is not always advisable to say octet arrangement refer to stable eight valence electrons.
Yes baking soda is dissolved in vinegar and bubbles appear is a CHEMICAL CHANGE .
Ooo that cool good thing I learn from this app
CaCI2 is for calcium chloride
The answer is B. The complete equation is C6H12O6 + 6O2 -->6H2O + 6CO2 + energy. So we can know that A and C and D is right. For B, the reaction release energy so it is exothermic reaction.
