Answer:
The change in temperature that occurs when 8000 J of heat is used by a mass 75 g of water is 25.4 °C
Explanation:
H = mc ΔT
m = 75 g
c = 4. 200 J/ g °C
H = 8000 J
ΔT =?
Rearranging the formula, making ΔT the subject of formula;
ΔT = H / m c
ΔT = 8000 / 75 * 4.200
ΔT = 8000 / 315
ΔT = 25.4 °C
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds. Elements: are pure substances made up of only l type of atom. Atoms of the same element are identical in properties.
Answer:
By absorbing energy electron is jump into higher energy level. This is called excitation.
Explanation:
The electron is jumped into higher level and back into lower level by absorbing and releasing the energy.
The process is called excitation and de-excitation.
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. For example if electron jumped from K to L it must absorbed the energy which is equal the energy difference of these two level. The excited electron thus move back to lower energy level which is K by releasing the energy.
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.
