Explore: Below the helium atom you see the isotope notation for helium-4. Add and subtract protons and neutrons a few times using the arrow buttons. Notice how the isotope notation changes when you do this. A. What does the top number equal?

hurricanes form in warm water

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.