Na releases 1 electron to be stable
Cl requires 1 electron to be stable
both are ionic bonded to be stable
Answer: The coefficient for 
is 12.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Thus in the reactants, there are 12 molecules of oxygen in balanced chemical equation. Thus the coefficient for is 12.
The Story Behind The Snowy Sour
As the air gets cooler and winter creeps in, I’m looking forward to the first snowfall of the season. This cocktail is all you will need to help you through. I took a classic sour cocktail and elevated it with a winter-citrus-infused simple syrup, made by combining clementine, orange, and honey with sugar and water. All the flavors came together really well, and the gin and fresh lemon juice amalgamate beautifully.
Ingredients In The Snowy Sour:
1.5 ounces gin
1 ounce lemon juice
¾ ounce winter citrus syrup
1 egg white
Snowy Sour Directions:
Combine all ingredients in a cocktail shaker with ice.
Shake hard to chill and combine.
Strain out ice.
Shake hard again to create a silky consistency.
Finely strain into your cocktail glass.
Garnish and enjoy!
Winter Citrus Simple Syrup Ingredients:
2 ounces clementine juice
2 ounces orange juice
2 ounces honey
2 ounces sugar
1 cup water
Winter Citrus Simple Syrup Directions:
Combine all ingredients into a small saucepan.
Bring to a boil.
Remove from heat element and stir while cooling.
Allow to sit for 30 minutes to an hour.
The given question is incomplete. The complete question is :
Which of the following Group 17 elements is the least reactive
a) Flourine
b) Chlorine
c) Astatine
d) Iodine
Answer: c) Astatine
Explanation:
Halogen is the name given to Group 17 family with general electronic configuration of 
which have 7 valence electrons and thus easily gain one electron to attain stable configuration.
As we move down the group from flourine to chlorine to bromine to iodine to astatine , the valence shell moves farther from nucleus and thus tendency to accept the electron decreases and thus reactivity also decreases.
Thus Astatine is the least reactive of all.
