Answer: 272.5915639999...
Explanation:
When you boil water, you aren't changing the elements. You're just making water vapor. However, when you burn paper, it becomes carbon (mostly). So physical changes will not change the substance, only chemical changes will.
The correct answer would be the last option. The property that is common to all group 2 elements is that they tend to form ionic bonds by losing electrons making these atoms positive charge. They are called cations. These elements are beryllium, magnesium, calcium, strontium, and radium.
