A&P Assignment #2 (Ch 2A)

After the transfer of the electron, sodium will form an ion with ______. a charge of -1 a charge of +1 an atomic number of 18 an atomic number of 10

a charge of +1 : If sodium loses an electron, it will be positively charged. Although not shown explicitly in the figure, the element sodium contains 11 protons within its nucleus. If sodium forms a cation containing 10 electrons, it will have a charge of +1.

The chloride ion (Cl-) indicated by the arrow is interacting most closely with which of the following? an oxygen atom within a water molecule a hydrogen atom within a water molecule another chloride ion a sodium ion

a hydrogen atom within a water molecule: The negatively charged chloride anion has dissociated from the salt crystal and formed an interaction with the positively charged hydrogen atoms of several water molecules.

A solution that has a pH of 2 could best be described as being ________. acidic slightly acidic basic neutral

acidic

What is the classification of a solution with a pH of 8.3? acidic solution alkaline solution neutral solution buffered solution

alkaline solution: A pH between 0.0 and 7.0 is acidic. A pH between 7.0 and 14.0 is basic. Therefore, a solution with a pH of 8.3 is an alkaline (or basic) solution.

Which particle is indicated by the arrow? electron proton neuron atom

proton: Note how the number of the indicated particles in each of the three atoms defines each as a unique element.

Based on the information in this figure, we can conclude that chlorine has an atomic number of ______. 11 10 17 18

17: The unbonded chlorine atom has 17 electrons. Therefore, chlorine must have 17 protons and an atomic number of 17

How many hydrogen atoms will nitrogen bond with to form a stable molecule? 2 1 3 5

3: Nitrogen has 5 electrons in its valence (outermost) electron shell. Therefore, it will form covalent bonds with three hydrogen atoms. Each single covalent bond includes the sharing of three pairs of electrons. The three electrons contributed by the hydrogen atoms will fill the valence shell of nitrogen.

How many valence shell electrons does the element carbon have? 2 8 4 6

4: Carbon is atomic number 6 and has four electrons in its outermost (valence) electron shell.

Which of the following accurately describes what is occurring in the illustrated reaction? A hydrogen bond is formed between carbon and the four hydrogen atoms. An ionic bond is formed between carbon and the four hydrogen atoms. A quadruple covalent bond is formed between carbon and one hydrogen atom. A single covalent bond is formed between carbon and each of the four hydrogen atoms.

A single covalent bond is formed between carbon and each of the four hydrogen atoms: Carbon shares a pair of electrons with each of the four hydrogen atoms. A pair of shared electrons is the basis of a single covalent bond

Hydrogen bonds are comparatively strong bonds. True False

False

Atomic number is equal to the number of neutrons in an atom's nucleus. True False

False: The atomic number of any atom is equal to the number of protons, not neutrons, in its nucleus

Which of the following is an example of a decomposition reaction? H2 + O → H2O MgSO4 + 2NaCl → MgCl2 + Na2SO4 2Na + Cl2 → 2NaCl MgO2 → Mg + O2

MgO2 → Mg + O2: A decomposition reaction occurs when a larger molecule is broken down into smaller molecules or its constituent atoms.

What explains the negative charge on the oxygen atom within the water molecule? Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen. Hydrogen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen. Protons are transferred from oxygen to hydrogen during the formation of an ionic bond. Electrons are transferred from hydrogen to oxygen during the formation of an ionic bond.

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen: Oxygen atoms are highly electronegative and pull electrons away from the electropositive hydrogen atom

Which of the following is TRUE regarding the pH of a solution? The more hydrogen ions in a solution, the more acidic the solution is. The fewer hydrogen ions in a solution, the more acidic the solution is. The more hydroxyl ions in a solution, the more acidic the solution is. The fewer hydroxyl ions in a solution, the more basic the solution is.

The more hydrogen ions in a solution, the more acidic the solution is: The more hydrogen ions in a solution, the more acidic the solution is.

What do these four elements have in common? They all have the same number of electrons in their first electron shell. They are all generally unreactive elements. They all have an incomplete valence electron shell. They all have the same number of protons in their nuclei

They all have an incomplete valence electron shell: The valence shell is the outermost electron energy level. Valence shell electrons determine the reactivity of an element

The lower the pH, the higher the hydrogen ion concentration. True False

True

Buffers help to stabilize blood pH. True False

True: Buffers are essential for stabilizing the pH of body fluids (such as blood). Note: buffers cannot prevent a change in pH, they can only resist or minimize the change (if acids or bases are added to the buffered solution).

What holds the sodium and chloride ions together in a chemical bond? the sharing of a pair of protons the sharing of a pair of electrons the attraction between their respective nuclei an electrical attraction between opposite charges

an electrical attraction between opposite charges: The transfer of an electron results in ions with opposite charges that are electrically attracted to each other

If an oxygen atom were to form a chemical bond in which it gained two electrons, it would ______. become less stable not change in terms of relative stability become more stable

become more stable: The addition of two electrons to the second electron shell of an oxygen atom would complete that energy level and result in increased stability.

The three atoms shown represent three unique ______. cells isotopes molecules elements

elements: The three atoms each contain different numbers of protons and are therefore unique elements

What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule? polar covalent bond ionic bond hydrogen bond nonpolar covalent bond

hydrogen bond: The attraction between the slightly negative oxygen atom of one molecule and the slightly positively charged hydrogen atom within a separate water molecule is the basis of hydrogen bond formation.

This figure depicts the formation of a(n) ______. nonpolar covalent bond hydrogen bond polar covalent bond ionic bond

ionic bond: An ionic bond is formed during the complete transfer of one or more electrons from one atom to another

Salts are always ________. double covalent compounds ionic compounds single covalent compounds hydrogen bonded

ionic compounds

Bonds between carbon and hydrogen atoms (as depicted on the right side of the figure) are generally ______. hydrogen bonds polar covalent bonds nonpolar covalent bonds ionic bonds

nonpolar covalent bonds: Neither carbon nor hydrogen is considered electronegative atoms. Therefore, neither atom has an overly strong pull on shared electrons, and those electrons are shared equally within a nonpolar covalent bond.

Sulfur is atomic number 16. Sulfur will form chemical bonds in a similar manner as ______. hydrogen oxygen carbon nitrogen.

oxygen: Oxygen and sulfur both have six electrons in their valence (outermost) electron shells. Therefore, they will form similar types and numbers of bonds with other atoms.

The lines drawn between hydrogen (H) atoms and the oxygen (O) atom in the structural diagram presented in the right of the figure each represent a ______. hydrogen bond polar covalent bond nonpolar covalent bond ionic bond

polar covalent bond: A covalent bond in which electrons are shared unequally is termed a polar covalent bond.

Amino acids joining together to make a peptide is a good example of a(n) ________ reaction. decomposition synthesis exchange reversible

synthesis

A chemical reaction in which bonds are broken is usually associated with ________. the consumption of energy a synthesis forming a larger molecule the release of energy

the release of energy

What is the most significant factor in the formation of a covalent bond? the attraction of a hydrogen atom nucleus to the electrons of another atom the complete transfer of one or more electrons from one atom to another the sharing of electron pairs between two atoms the transfer of one or more protons from one atom to another

the sharing of electron pairs between two atoms: Covalent bonds are formed by the sharing of electrons between two reactive atoms

Which of the following is not considered a factor in influencing a reaction? time particle size temperature concentration

time