7. Despite the fact that the solubility rules have the word "rules" in the title, there are several exceptions to each that don't make much sense. The instance above shows a two of them.
In the space below, identify which rule each compound breaks and modify the rule to fit it.
Hint: For example if Magnesium Carbonate was soluble, we would modify the first rule to say: "Carbonate, Phosphate, and Hydroxide
salts are insoluble, except for Magnesium Carbonate."

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.  

a basic emergency supply kit could include the following recommended items: water - one gallon of water per person per day for at least three days, for drinking and sanitation. food - at least a three-day supply of non-perishable food. battery-powered or hand crank radio and a noaa weather radio with tone alert.