Answer:
Fr
Explanation:
Francium (Fr) has the lowest ionization energy, with a value of 4.0727eV. This ionization energy increases as one advances in a period, being greater in the group of nonmetals.
First one because Common synthetic materials are nylon, acrylic, polyester, carbon fiber, rayon and spandex. Synthetic materials are made from chemicals and are usually based on polymers. They are stronger than natural and regenerated materials.
Answer:
a) equilibrium shifts towards the right
b) equilibrium shifts towards the right
c) equilibrium shifts towards the left
d) has no effect on equilibrium position
e) has no effect on equilibrium position
Explanation:
A reversible reaction may attain equilibrium in a closed system. A chemical system is said to be in a state of dynamic equilibrium when the rate of forward reaction is equal to the rate of reaction.
According to Le Chateliers principle, when a constraint such as a change in temperature, pressure, volume or concentration is imposed upon a system in equilibrium, the equilibrium position shifts in such a way as to annul the constraint.
When the concentration of reactants is increased, the equilibrium position is shifted towards the right hand side and more products are formed. For an endothermic reaction, the reverse reaction is favoured by a decrease in temperature. Increase in pressure has no effect on the system since there are equal volumes on both sides of the reaction equation. Similarly, the addition of a catalyst has no effect on the equilibrium position since it speeds up both the forward and reverse reactions to the same extent.
The movement of rock pieces and other materials on earth's surface is called Weathering
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