Using the idea that reactions occur as a result of collisions between particles, explain why reaction rates depend on the concentration of the reactants.

Since reactions occur as a result of collisions between particles, the more particles are in a reaction vessel, the higher the concentration of particles, the more collisions are possible. The more collisions that occur, the faster the reaction rate.

Explanation:

These are just some characteristics for a reaction to occur

"a connection, a bond or common feeling between two people", or as a chemical process it stimulates love or sexual attraction

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.