Chapter 13 Study Review

Molecules

Groups of atoms held together by covalent bonds are called: a. elements. b. molecules. c. mixtures. d. alloys.

binary

A chemical compound that consists of two elements is known as a ________________

Molecule

A group of atoms that forms a compound held together by covalent bonds is called a ____________________

carbon

All organic molecules contain the element ____________________.

Lithium and fluorine atoms

An ionic bond is most likely to form between: a. carbon and oxygen atoms. b. lithium and fluorine atoms. c. two oxygen atoms. d. nitrogen and oxygen atoms.

Electrons in an atom's outermost energy levels (known as valence electrons) may be gained or lost to complete an octet (eight valence electrons). When electrons are lost or gained, the atom becomes charged. This charge causes the atom to be attracted to atoms with an opposing charge. This kind of attraction usually results in the formation of an ionic bond. When atoms have roughly equal tendency to accept electrons they share electrons to form covalent bonds. Elements that are nonmetals and therefore close together on the periodic table tend to form covalent compounds because they have a nearly equal tendency to accept electrons.

Briefly explain the difference between ionic and covalent bonding.

Carbohydrate

Cellulose is a type of organic molecule identified by scientists as a: a. carbohydrate. b. lipid. c. protein. d. nucleic acid.

2 electrons

Chemical formulas represent the number and element of each type of atom in: a. covalent compounds only. b. ionic compounds only. c. both ionic and covalent compounds. d. mixtures only.

both ionic and covalent compounds.

Chemical formulas represent the number and element of each type of atom in: a. covalent compounds only. b. ionic compounds only. c. both ionic and covalent compounds. d. mixtures only.

20

How many different amino acids ar einvolved in making the thousands of proteins in the human body? a. 4 b. 20 c. 26 d. 90

6

How many electrons are shared between two atoms covalently bonded by a triple bond? a. 2 b. 3 c. 6 d. 9

potassium chloride

Name the ionic compound formed by combining K and Cl.

Sugar Molecule, Phosphate Molecule, Base Molecule

Name the three types of molecules present in each nucleotide.

nucleotides

Nucleic acids are compounds made of long, repeating chains called ____________________.

KCl

Predict the chemical formula of the compound formed when the two elements, K and Cl, combine.

K= 1+, Cl = 1-

Predict the oxidation numbers for potassium (K) and chlorine (Cl).

loses,gains

Sodium forms an ionic bond with chlorine when sodium ____ an electron and chlorine ____ an electron. a. shares, shares b. loses, gains c. gains, loses d. loses, loses

Fluorine contains seven valence electrons. It needs one more electron to complete its octet. The oxidation number is 1- and indicates fluorine will gain or share one electron when it combines with another atom to become a more stable compound.

State fluorine's oxidation number and its number of valence electrons. Explain the significance of each.

loses two electrons

The Mg atom becomes the ion, Mg2+, when it: a. gains two electrons. b. loses two electrons. c. gains two protons. d. loses two protons.

Lithium, atomic number is 4

The atom of the element most likely to bond with a single atom of fluorine, atomic number 9 is: a. lithium, atomic number 3. b. beryllium, atomic number 4. c. boron, atomic number 5. d. carbon, atomic number 6.

Spinach

The food lowest in cholesterol is most likely: a. fish. b. turkey. c. ham. d. spinach.

7

The most common oxidation number for an element in the second period is 3-. The atomic number of the element is: a. 3. b. 5. c. 7. d. 11.

Elements with negative oxidation numbers are usually listed first.

The most common oxidation number for an element in the second period is 3-. The atomic number of the element is: a. 3. b. 5. c. 7. d. 11.

Chemical bonds are formed only between the electrons in the highest unfilled energy level. The highest energy level for a neon atom is filled, containing eight valence electrons in its outermost level.

The neon atom pictured below does not bond with other atoms frequently. Why?

Oxidation

The quantity indicating the charge on an atom when an electron is lost, gained or, shared during bond formation is called the ____________________ number.

Triangles

The three basic forms of organic molecules include all of the following EXCEPT: a. rings. b. chains. c. triangles. d. branches.

2

What is the largest number of valence electrons that an atom in the first period can have? a. 1 b. 2 c. 8 d. 18

0

What is the oxidation number of a molecule of water, formed when two hydrogen atoms (oxidation number 1+) and one oxygen atom (oxidation number 2-) bond? a. 0 b. 1+ c. 1- d. 2-

Its chemical formula ( the ratio of atoms) and structure

What two factors determine the properties of a compound?

LiOH

Which of the following contains a polyatomic ion? a. NaCl b. H2O c. Fe2O3 d. LiOH