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 :)
Answer:
The reasons that cities boomed during the Middle Ages are more employment opportunities, increased trade, and growing interest in culture and art.
These spring<span> tides occur because the Sun and Moon's gravity tug on Earth together. Weaker, or neap, tides happen when the Sun, the Moon, and Earth form an L-shape. Good Luck! So the answer in short is spring tide.</span>
