Question

22 Unit 1 The Body as a Whole EXERCISE 2-2: Parts of the Atom, Molecule of Water (Text Figs. 2-2 and 2-6) Oxygen 1. This figure illustrates two hydrogen atoms and one oxygen atom. Write the names of the parts of the atom (electron, proton, neutron) on the appropriate lines in different, darker colors. 2. Color the electrons, protons, and neutrons on the figure in the appropriate colors. You should find 10 electrons, 10 protons, 0 and 8 neutrons in total. 3. Use two contrasting, light colors to shade the first energy level (4) and the second energy level (5). 4 2. Hydrogen Hydrogen 5. 3. DIFFERENTIATE BETWEEN IONIC AND COVALENT BONDS. See Exercise 2-3. 4. DEFINE AN ELECTROLYTE. EXERCISE 2-3 Write the appropriate term in each blank from the list below nonpolar covalent polar covalent cations ionic electrolytes anions 1. Negatively charged ions 2. A bond formed by the equal sharing of electrons between two atoms 3. Compounds that form ions when in solution 4. Positively charged ions 5. A bond formed by the transfer of electron(s) from one atom to another 6. A bond formed by the unequal sharing of electrons between two atoms

Answer 1

Exercise 2-2

In the oxygen atom,

1- Proton

2- Neutron

3- Electron

4- Neutron

5- The atom

In the hydrogen atom,

1- Proton

4- The atom

DIFFERENCE BETWEEN IONIC AND COVALENT BOND

1. Ionic compounds are formed from strong electrostatic interactions between ions. Covalent compounds have bonds where electrons are shared between atoms.

2. Ionic bonding occurs between a nonmetal, which acts as an electron acceptor, and a metal, which acts as an electron donor. These bonds mostly occur between nonmetals or between two of the same (or similar) elements.

3. At room temperature and normal atmospheric pressure, covalent compounds may exist as a solid, a liquid, or a gas, whereas ionic compounds exist only as solids.

4. Although solid ionic compounds do not conduct electricity because there are no free mobile ions or electrons, ionic compounds dissolved in water make an electrically conductive solution. In contrast, covalent compounds do not exhibit any electrical conductivity, either in pure form or when dissolved in water.

5. Ionic compounds exist in stable crystalline structures. Therefore, they have higher melting and boiling points compared to covalent compounds.

4. ELECTROLYTE - An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water.

EXERCISE 2-3

1. ANION

2. NON POLAR COVALENT

3. ELECTROLYTE

4. CATION

5. IONIC

6. POLAR COVALENT