Rows of elements are called periods. The period number<span> of an element signifies the highest unexcited energy level for an electron in that element.
</span>Columns of elements help define element groups<span>. </span>Elements within a group share<span> several common properties. Groups are elements have the same outer electron arrangement.</span>
The heat absorbed by the water is
Q = 500 (4.18) (32.2 - 25)
Q = 15048 J
The enthalpy of fusion of the sodium acetate is:
<span>ΔHf = Q / m
</span><span>ΔHf = 15048 / 100
</span>ΔHf = 150.48 J/g
Answer:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations.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
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 because electron can not stay longer in higher energy level and comes to ground state.
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 kinetic energy and the physical state of water depend strongly on the temperature;
- Firstly, The kinetic energy of water on a hot stove is higher than that on the counter in the freezer; that the kinetic energy is directly proportional to the temperature according to the relation:
; where R is the universal gas constant, T is the temperature and NA is Avogadro number.
As the temperature increases, the speed of colliding molecules increases and the kinetic energy increases.
- Secondly, The physical state of water depends on the temperature; water has three states (gas, liquid and solid) depends on the temperature.
- If a glass of water is putt on the counter in the freezer, it will be converted to the solid state (ice).
- And, as if it is putt on a hot stove, it will be vapor (gaseous state).
