Answer : first opinion and also last
Expiation : Note that these last two reactions, and 2H + 2H → 4He + γ, .Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. Nuclear fusion is a reaction in which two nuclei are combined, or fused, to form a larger nucleus. We know that all nuclei have less mass than the sum of the masses of the protons and neutrons that form them. The missing mass times c2 equals the binding energy of the nucleus—the greater the binding energy, the greater the missing mass.
Answer: option C. HF
Explanation: A polar bond is a covalent bond between two atoms where the electrons forming the bond are unequally distributed. Fluorine is more electronegative than hydrogen so the electrons in the bond are more closely associated with the fluorine atom than with the hydrogen atom.
Answer: option D. The attractive forces between the sodium and chloride ions are overcome by the attractive forces between the water and the sodium and chloride ions.
Explanation:
<em>Solid sodium chloride</em> (NaCl) is a ionic compound formed by ionic bonds between by the positive, metallic cations of sodium atom, Na⁺, and the negative, non-meatllic anions of chlorine atom, Cl⁻ (chloride).
Ionic bonds, then, are the electrostatic attracion between oppositely charged particles (cations and anions).
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<em>When solid sodium chloride dissolves in water</em>, the ions (cations and anions) are separated in the solvent (water) due to the superior attracitve forces between such ions and the polar water molecules.
<em>Water</em> (H₂O) is a molecule, formed by polar covalent bonds between two hydrogen atoms and one oxygen atom.
The polarity of water molecule is due to the fact that oxygen atoms are more electronegative than hydrogen atoms, which cause that the electron density is closer to oxygen nuclei than to hydrogen nuclei. This asymmetry in the electron density conferes a partial positive charge over each hydrogen atom and a partial negative charge over the oxygen atoms.
Thus, the positively charged hydrogen atoms attract and surround the negative chloride (Cl⁻) anions, while the negatively charged oxygen atoms attract and surround the positive sodium (Na⁺) cations. It is only because the attractive forces between the water and the sodium and chloride ions are stronger than the attractive forces between the sodiium and chloride ions that such ions may be kept separated in the solution. This process is called solvation and the ions are said to be solvated by the water molecules.
Answer:Answer: The step that is NOT necessary to complete before a cuvette is placed into the spectrophotometer is option B (Write, in ink, either sample or blank on the side of the cuvette to keep track of them)
Explanation: spectrophotometer is an instrument used to measure the light intensity absorbed after being passed through a solution. Before the absorbance of the sample solution, a solvent solution called blank is used for the calibration of the machine and this blank solvent is placed in a cuvette. The procedure usually comes first before the main sample is processed. Therefore there is no need to
Write, in ink, either sample or blank on the side of the cuvette to keep track of them. This is so since sample and blank is not absorbed at the same time by the machine.