The frequency of wave x is 500 hz and the wave length is 60 cm. the frequency of wave y is 520 hz and the wave length is 50 cm. which is the fastest wave?

it's c. elements are placed in rows based on how may valencies electrons have.

that's what i got you can count the number of atoms

answer; 4 electrons;

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.