Ca-Cl is an ionic bond. We know this because the difference between their electronegativities is 2.16.The electronegativity tells us which atom will attract the electron more than the other. Hence, chlorine attracts the electron a lot more than the calcium.A difference of more than 1.6 (or 1.7 depending on the source) implies that the electrons are so unevenly shared, that the bond is ionic, rather than polar covalent.
Explanation: This is a reaction of oxidation of 
in the presence of acidified 
. Acidified is a strong oxidizing agent.
To balance out the 
on the reactant side, we write 
on the product side.
Balancing out the following reaction gives us:
The best answer is the isotope of strontium which is strontium-85. It has a half-life of about 64 days. The metal strontioum has four stable, naturally occurring isotopes which includes 84Sr (0.56%), 86Sr (9.86%), 87Sr (7.0%) and 88Sr (82.58%).
A change in the Earth's magnetic<span> field resulting in the </span>magnetic<span> north being aligned with the geographic south, and the </span>magnetic<span> south being aligned with the geographic north. Also called </span>geomagnetic reversal<span>.</span>
