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 :)
Set up a proportion: Central Angle/360= arc length/ circumference where the central angle= 45 and circumference= 128 ft. After you cross multiply, you should find that the answer is 16ft which is A.
People live in mud or stone one-room houses
Explanation:
because in rural village we cannot find it
