A= Molds and cast fossils
B= Petrification Fossils
C= Whole Body Fossils
D= Footprints and Trackways
Answer:
single replacement reaction is type of reaction is Au2S+H2---> 2Au+H2S.
Energy levels inside an atom are the specific energies that electrons can have when energy occupies specific orbitals. Electrons can be excited to higher energy levels by absorbing energy from the surroundings, an equivalent light is emitted when an electron returns from a high energy state to a lower one. Representation of this diagrammatic is known as the energy level diagram.
