Balanced chemical reaction:
2Na₃PO₄(aq) + 3CaCl₂(aq) → 6NaCl(aq) + Ca₃(PO₄)₂(s).
Ionic reaction:
6Na⁺(aq) + 2PO₄³⁻(aq) + 3Ca²⁺(aq) + 6Cl⁻(aq) → 6Na⁺(aq) + 6Cl⁻(aq) + Ca₃(PO₄)₂(s).
Net ionic reaction: 2PO₄³⁻(aq) + 3Ca²⁺(aq) → Ca₃(PO₄)₂(s).
<span>(aq) means that
substances are dissociated on cations and anions in water.
</span>(s) means solid.
The car's velocity after 5s : 10 m/s
<h3>Further explanation</h3>
Given
velocity=v=72 km/h=20 m/s
time=t = 5 s
acceleration=a = -2 m/s²
Required
velocity after 5s
Solution
Straight motion changes with constant acceleration
vf=final velocity
vi = initial velocity
Input the value :
The car is decelerating (acceleration is negative) so that its speed decreases
Answer:
b is the anwer
Explanation:
the option is the explanation
Answer:
The transition from lower energy level to higher energy level require a gain of energy.
Explanation:
When transition occur from lower energy level to higher energy level require a gain of energy. Electron could not jump unto higher energy level without gaining thew energy.
When electron jump into lower energy level from high energy level it loses the energy.
For example electron when jumped from 2nd to 3rd shell it gain energy and when in return back to 2nd shell from 3rd shell it loses 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.
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.
