b. the ozone layer
c. banded iron formations
d. stromatolites
Banded iron formations
Before free oxygen gas became abundant in the oceans and atmosphere, it reacted with a metal and produced banded iron formations.
(2) organization of atoms in a crystal
(3) radioactive nature of some atoms
(4) spectra of elements with multielectron atoms
The wave-mechanical model of the atom explains the spectra of elements with multielectron atoms by describing electrons as wave-like particles with discrete energy levels. This leads to the unique patterns of spectral lines observed for different elements.
The wave-mechanical model of the atom is used to explain the spectra of elements with multielectron atoms. The model, also known as the quantum mechanical model, describes electrons as wave-like particles with discrete energy levels. These energy levels give rise to the unique spectral lines observed for different elements.
For example, when an electron in an atom absorbs energy, it jumps to a higher energy level. When it returns to its original energy level, it releases the absorbed energy in the form of light. Each element has its own set of energy levels, leading to a unique pattern of spectral lines.
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b. ecology d. food chain
Molecular compounds can not conduct electricity because they do not break up into ions. Therefore, option (A) is correct.
Molecular compounds can be characterized as those compounds where the atoms are connected by covalent bonds. The covalent bond is generally created by the mutual sharing of electrons by the atoms. In molecular compounds, intermolecular forces are responsible for bond formation.
The melting point of the molecular compound is low as compared to the ionic compound as the energy required to break bonds is less compared to the ionic bond between ions in the crystalline ionic compound.
Molecular compounds are generally by the reaction between non-metals. Molecular compounds are also known as covalent compounds. The ionic and molecular compound differ from each in their physical properties,
The molecular compounds do not conduct electricity as they do not bark into ions. Therefore they can behave as insulators while ionic compounds conduct electricity.
Learn more about Molecular compounds, here:
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