24. <span>Valence electrons are most loosely held by the atom and are involved in chemical reactions. Chemical reactions occur when valence electrons are shared between atoms. The number of valence electrons determines how these reactions take place and what kind of bonds they form.
25 </span><span>Sodium has one valence electron and chlorine has seven valence electrons. The Ione valence electron from sodium is lost and is transferred to the chlorine atom. The result is a sodium ion with a charge of 1+ and a chloride ion with a charge of 1-. The oppositely charged ions attract each other and the charges balance to make a compound that is electrically neutral.
26. </span><span>Ionic compounds have high melting points and high boiling points compared to molecular compounds. Ionic compounds that are dissolved in water or melted will conduct electricity. Molecular compounds do not conduct electricity in either case.
27. </span><span>A covalent bond is formed when two atoms share valence electrons. Neither atom loses electrons or takes electrons from the other. No charged particles form. In an ionic bond, one or more electrons are transferred from one atom to another. Atoms that lose electrons become positively charged ions, and atoms that gain electrons become negatively charged ions. These oppositely charged particles then attract each other.
28. </span><span>A metal crystal consists of positively charged metal ions embedded in a "sea" of loosely held valence electrons that can move around easily. Heat travels through materials as the increased motion of the particles in the hotter parts of the material is passed along to the particles in the cooler parts. In a metal, since particles are easily set in motion, heat is easily transferred or conducted. The same is true for the conduction of electricity. Electricity can flow when charged particles, such as electrons, are free to move. Since the electrons in a metal crystal can move freely among the atoms, electricity is easily conducted.</span>
<u>Answer:</u> The pH of the solution is 9.71
<u>Explanation:</u>
1 mole of NaOH produces 1 mole of sodium ions and 1 mole of hydroxide ions.
We are given:
pOH of the solution = 7.2
To calculate the pH of the solution, we need to determine pOH of the solution. To calculate pOh of the solution, we use the equation:
![pOH=-\log[OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%5BOH%5E-%5D)
We are given:
![[OH^-]=5.09\times 10^{-5}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D5.09%5Ctimes%2010%5E%7B-5%7DM)
Putting values in above equation, we get:
To calculate pH of the solution, we use the equation:
Hence, the pH of the solution is 9.71
- Answer: <em><u>The compounds containing CFCs (chlorofluorocarbons) are mainly responsible for ozone layer depletion as these compounds react with ozone in the presence of ultraviolet rays to form oxygen molecule and thus, destroying ozone.</u></em>
Explanation: <em><u>Human activities cause the emission of halogen source gases that contain chlorine and bromine atoms. These emissions into the atmosphere ultimately lead to stratospheric ozone depletion. The source gases that contain only carbon, chlorine, and fluorine are called chlo- rofluorocarbons usually abbreviated as CFCs.</u></em>
Answer:
Ethanol has covalent intramolecular bonds. Ethanol is polar. Ethanol has dispersion intermolecular forces. Dimethyl ether is polar. Dimethyl ether forms hydrogen bonds. Dimethyl ether has dispersion intermolecular forces.
Explanation:
Ethanol is not a carboxylic acid. It is an alcohol and it has covelent intramolecular bonds. It is polar and it also has dispersion intermolecular forces.
Dimethyl ether is also polar and it has forms hydrogen bonds. It also has dispersion intermolecular forces. Dimethyl ether does not have ionic intramolecular forces
C. Digesting a sandwich
Is your answer
Hope this helps
