The mass number of an element is equivalent to the number of Protons and Neutrons in the element. For example Oxygen has eight protons and neutrons, therefore its mass number is 16. You could also calculate this by simply rounding the atomic weight of the element to the nearest whole number. Oxygen's atomic weight is 15.994, which as you can see, would be rounded to 16 :)
75-79? I think that is what is; the shape are so similar so its kinda hard to tell
Answer:
I'm not sure but I think it is convection.
The Great Lakes — Superior, Huron<span>, </span>Michigan<span>, </span>Ontario<span> and Erie — make up the largest body of fresh water on Earth, accounting for one-fifth of the freshwater surface on the planet at 6 quadrillion gallons</span>