A volcano valley. Volcanic ash is a good sorce for fertilizer
Answer: A - it is changing into a new substance
the other answers are just physical changes
The given chemical reaction is:
Δ
∑BE(reactants)-∑BE(products)
= {(941 kJ/mol) + (3 * 242 kJ/mol)} -[{2*(3*200 kJ/mol)}]
= 467 kJ/mol
Calculating the change in heat when 85.3 g chlorine reacts in the above reaction:
Moles of chlorine = 
= 1.20 mol 
Heat change when 1.20 mol chlorine reacts
= 
Answer:
Option C= light is emitted as electron falls from the excited state to the ground state releasing a photon.
Explanation:
Electrons are responsible for the production of colored light.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10⁻³¹ Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
How electrons produce the colored light:
Excitation:
When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.
De-excitation:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.
The specific heat capacity of the metal is calculated using the following formula
Q(heat)= MC delta T
Q= 1495 j
c= specific heat capacity =?
M(mass)=319 g
delta T = change in temperature = 66-55 =11 c
by making c the subject of the formula
C=Q /M delta T
c= 1495 j/ 319 g x 11 c =0.426 j/g/c
