Does standard atmospheric pressure correspond to the normal air pressure at sea level.

Yes

Explanation:

Standard temperature and pressure conditions are defined as 1 atm pressure and 273.15 K. On the other hand, standard ambient temperature and pressure conditions are defined as 1 atm pressure and 298.15 K.

Notice, however, that the only change between them is in temperature.

In any standard conditions, the standard atmospheric pressure is equal to 1 atm.

At sea level, the atmospheric pressure is also equal to 1 atm.

Therefore, we may conclude that the standard atmospheric pressure is equivalent to the normal air pressure at sea level. With an increase in altitude, however, the atmospheric pressure decreases.

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.