H₂O + H₂O ⇌ H₃O⁺ + OH⁻
You use two single-barbed arrows pointing in opposite directions (technically rightwards harpoon over leftwards harpoon) <em>to indicate a reversible reactio</em>n.
Answer:
The answer is C, both krypton and neon.
Explanation:
I got the answer wrong and my teacher told me that c is the right answer choice
A national day is a day on which celebrations mark the nationhood of a nation or state. It may be the date of independence, of becoming a republic, or a significant date for a patron saint or a ruler (such as a birthday, accession, or removal). The national day is often a public holiday.
Answer: 4.04 ounce
Explanation: Given: Peanut butter contained in the jar = 1.43 kg
Used Peanut butter=8.0 % of 1.43kg = 
As we know 

This uses the concept of freezing point depression. When faced with this issue, we use the following equation:
ΔT = i·Kf·m
which translates in english to:
Change in freezing point = vant hoff factor * molal freezing point depression constant * molality of solution
Because the freezing point depression is a colligative property, it does not depend on the identity of the molecules, just the number of them.
Now, we know that molality will be constant, and Kf will be constant, so our only unknown is "i", or the van't hoff factor.
The van't hoff factor is the number of atoms that dissociate from each individual molecule. The higher the van't hoff factor, the more depressed the freezing point will be.
NaCl will dissociate into Na+ and Cl-, so it has i = 2
CaCl2 will dissociate into Ca2+ and 2 Cl-, so it has i = 3
AlBr3 will dissociate into Al3+ and 3 Br-, so it has i = 4
Therefore, AlBr3 will lower the freezing point of water the most.