Explanation:
According to the law of the conservation of mass, 'mass is conserved in a chemical reaction. The mass cannot be created nor be destroyed in a chemical process'.
This law holds true for the burning of wood also. Although the wood burns to produce ash which weighs less than wood but also, it produces some soot and other gases and the sum of the masses of all these is equal to the sum of the masses of wood and oxygen that reacted with it.
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.
Answer:
6.67 M
Explanation:
Molarity = 
<em>Convert 200g NaOH to moles. Convert 750 mL to L.</em>
200 g NaOH x (1 mol/39.998 g) = 5.00025... mol NaOH
750 mL x (1 L/1000 mL) = 0.750 L
<em>Substitute values into the equation.</em>
Molarity = 
Molarity = 6.667... M
Molarity = 6.67 M
There are two terms
a) accuracy : it relates to the exactness of an answer that how an answer is close to the actual answer or actual reading
So 104.6 is accurate
b) Precision : This is related to the closeness of different readings with each other
The first reading is 103.7 and the second one is 108.4 so the second reading is quite different from the first reading so it cannot be called as precised
Again 105.8 has good difference from the second reading hence again this is not precised
However the last reading 104.6 is quite near to 105.8 so 104.6 can be called as precise
