The word equation for the reaction is: iron + chlorine iron chloride
Iron chloride is a solid.
The teacher weighed the glass tube and contents:
. before the reaction
. after the reaction.
What happened to the mass of the glass tube and contents during the reaction?
Give one reason for your answer.

it's filtration, but this is an assumption so my apologies if i got this

let that person have a turn to speak : )

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.