The chemical formula for naphthalene is c10h8. it’s used to make mothballs and pesticides.
in 4c10h8, the coefficient , the subscript of carbon , and the subscript of hydrogen .

The chemical formula for naphthalene is C10H8. It’s used to make mothballs and pesticides.

In 4C10H8, the coefficient is 4 , the subscript of carbon is 10 , and the subscript of hydrogen is 8 .

Explanation:

The subscript value of a chemical formula is used to represent the actual number of atom present in the original compound . The compounds name is Naphthalene and the subscript value represent the original number of atom present in the compound. The subscript value remains same for the compound. If the sub scripted value change it becomes another compound.  From the sub scripted value Naphthalene has 10 atoms of carbon and 8 atom of hydrogen.  

The coefficient value is used  when balancing a chemical equation or to show the number of moles of the actual compound . The 4 depicts that the compound has four moles of Naphthalene. If the coefficient value is changed the compound still retains it name but the quantity is altered in moles. Example  5C10H8 is five moles of Naphthalene.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.