What determines an element's emission spectrum? O A. The size of the sample
O B. The mass of the nucleus
O C. The electron energy levels
O D. The number of protons

answer: - first one is the correct answer. .

explanations: - potassium sulfide is and cobalt(ii) chloride is .

charge on k is +1, charge on s is -2, charge on co is +2 and charge on cl is -1.

in a double replacement reaction the ion exchange takes place. in general the reaction looks like:

if one of the product is insoluble as per solubility rules then a precipitate of it is formed.

when we mix the aqueous solutions of potassium sulfide and cobalt(ii) chloride then chloride ion goes with potassium ion and sulfide ion goes with cobalt ion and the balanced equation is written as:

k and cl has equal charges, similarly co and s has equal charges and hence no subscripts are used for the product side.

as per the solubility rules, cos is insoluble and so it's precipitate is formed.

looking at the given choices, first choice is correct.

dipole moments occur when there is a separation of charge. they can occur between two ions in an ionic bond or between atoms in a covalent bond; dipole moments arise from differences in electronegativity. the dipole moment is a measure of the polarity of the molecule.

explanation:

in inorganic chemistry -dipole moment ( μ ) is the measure of net molecular polarity, which is the magnitude of the charge q at either end of the molecular dipole times the distance r between the charges. μ = q × r.