Practice MCQ Questions and answers on Chemistry-GK

Neutrinos do not carry electric charge, and have mass quite small, though non-zero. Their mass is tiny even by the standards of subatomic particles. They are electrically neutral, weakly interacting elementary subatomic particles with half-integer spin.

Quantum numbers may be defined as a set of four numbers which give complete information about the electron in an atom, i.e., energy, orbital occupied, size, shape and orientation of that orbital and the direction of electron spin. Magnetic quantum number is required to explain the fact that when the source giving the line spectrum is placed in a magnetic field, each spectral line splits in to a number of lines. The magnetic quantum number tells the number of orientations which the orbitals present within the same sub-shell can take up.

John Dalton (1766-1844) developed the first useful atomic theory of matter.

The most suitable unit for expressing nuclear radius is Fermi.

The total energy of a revolving electron in any orbit is the sum of its kinetic and potential energies. Energy of an electron at infinite distance from the nucleus is zero. As an electron approaches the nucleus, the electron attraction increases and the energy of electron decreases and thus becomes negative. Thus, it can never be positive.

Fertilizers typically provide, in varying proportions: (i) six macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S); and (ii) eight micronutrients: boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn) and nickel (Ni).

Higher concentration of Nitrogen and Phosphorus causes Eutrophication.

Oxidized forms of nitrogen include nitrite (NO₂) and nitrate (NO₃). Nitrogen mainly occurs in wastewater in this form. Because nitrite is easily oxidized to nitrate, nitrate is the compound predominantly found in groundwater and surface waters.

If all bullets could not be removed from gun shot injury of a man, it may cause poisoning by lead.

More than 90% of world production of urea is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. Therefore, it has the lowest transportation costs per unit of nitrogen nutrient.