Monique hears on the weather report that cold, dry air from Canada is going to hit warm, moist air from the Gulf of Mexico. She should expect a:

She should suspect a Tornado.

Explanation:

Tornadoes form when warm humid air collides with cold dry air. The denser the cold air is pushed over warm air, causing an updraft. As soon as it reaches the ground a tornado is formed.

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.  

4d^55s^1 ( third choice)