Answer:
They are heavy metals.
Explanation:
Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers.
It must be made of matter because anything and everything is made up of atoms. The other three options are made of atoms but they are also matter.
Answer:
Change in internal energy (ΔU) = -9 KJ
Explanation:
Given:
q = –8 kJ [Heat removed]
w = –1 kJ [Work done]
Find:
Change in internal energy (ΔU)
Computation:
Change in internal energy (ΔU) = q + w
Change in internal energy (ΔU) = -8 KJ + (-1 KJ)
Change in internal energy (ΔU) = -8 KJ - 1 KJ
Change in internal energy (ΔU) = -9 KJ
Answer:
when electron emit the radiations it means it jumped to the lower energy level from higher energy level.
Explanation:
When electron jump into lower energy level from high energy level it loses the energy.
The process is called 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.
