In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause's principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gausses principle, one of the species is to be eliminated in due course of time, but both are surviving. How? And what possibly happened to both the species?

It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term "metallic radius" which is taken as half the inter nuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: Which of the following relations is correct, if considered for the same element.

It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term "metallic radius" which is taken as half the inter nuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: K^(+), CI^(-), Ca^(2+), S^(2-) ions are isoelectronic. The decreasing order of their size is:

It is not possible to measure the atomic radius prectsely since the electron cloub surrouding the atom does not have a sharp boundary. One practial approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound togther by a signle bond in a covalent molecule and then dividing by two. For metals we define the term "matellic radius" which is taken as half the internuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomis radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: Which of the following relations is correct, if considered for the same element.

It is not possible to measure the atomic radius prectsely since the electron cloub surrouding the atom does not have a sharp boundary. One practial approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound togther by a signle bond in a covalent molecule and then dividing by two. For metals we define the term "matellic radius" which is taken as half the internuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomis radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: C^(+), CI^(-), Ca^(2+), S^(2-) ions are isoelectronic. The decreasing order of their size is:

It is not possible to measure the atomic radius prectsely since the electron cloub surrouding the atom does not have a sharp boundary. One practial approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound togther by a signle bond in a covalent molecule and then dividing by two. For metals we define the term "matellic radius" which is taken as half the internuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomis radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: Select the INCORRECT option regarding atomic//ionic sizes:

It is not possible to measure the atomic radius prectsely since the electron cloub surrouding the atom does not have a sharp boundary. One practial approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound togther by a signle bond in a covalent molecule and then dividing by two. For metals we define the term "matellic radius" which is taken as half the internuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomis radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: Select the INCORRECT option regarding atomic//ionic sizes:

Assertion : Elimination of a competitively inferior species in a closely related or otherwise similar group is known as competitive exclusion principle. Reason : If two species compete for the same resource, they could aviod competition by choosing different times for feeding or different foraging patterns.