Ch 2B
After the transfer of the electron, sodium will form an ion with __________.
a charge of +1
Chemical reactions progress at a faster rate when the _____
reacting particles are present in higher numbers
Catalysts increase the rate of chemical reactions, sometimes while undergoing ______
reversible changes in shape
Which of the following is a product in the following reaction? glucose + fructose → sucrose + H2O
sucrose
Calcium's atomic number is 20. It forms ions with 18 electrons. What is the electrical charge of a calcium ion?
+2
Define ionic bond
A bond in which electrons are completely lost or gained by the atoms involved.
An atom with 3 electrons in its outermost (valence) shell may have a total of ________ electrons altogether.
13
Based on the information in this figure, what is the atomic number of chlorine?
17
Define non-polar covalent bond
A bond in which electrons are shared equally.
Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)?
7
Define hydrogen bond
A type of bond important in tying different parts of the same molecule together into a three-dimensional structure.
In a covalent bond,
Atoms share one or more pairs of electrons.
Examine the following reactions. Which of the following is true about compound C? Reaction 1: A + B → Reaction 2: C + D → Reaction 3: E + F → Reaction 4: G + H
C is the product of reaction 1 and a reactant for reaction 2.
Define molecule
Combination of two or more atoms of the same element held together by chemical bonds
Define cation
Electrically charged particle due to loss of an electron
Rank the chemical bonds from relatively weakest to strongest. I. Ionic II. Covalent III. Hydrogen
III < I < II
How do ions form ionic bonds?
Ions of opposite electrical charges are attracted to each other to balance the charges.
Define neutron
Neutral subatomic particle
Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?
No, because the atoms have only 6 valence electrons, but need 8 for stability.
Which of the following distinguishes hydrogen bonds from covalent bonds?
Only hydrogen bonds can form between molecules.
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.
Define atom
Smallest particle of an element that retains its properties.
T/F A chemical bond is an energy relationship between outer electrons and neighboring atoms.
TRUE
T/F Hydrogen bonds are too weak to bind atoms together to form molecules, but they do hold different parts of a single large molecule in a specific three-dimensional shape.
TRUE
Which of the following is true of polar covalent bonds?
The electrons are shared unequally.
What do these four elements have in common?
They all have an incomplete valence electron shell.
How are the oxygen atoms bonded together in a molecule of oxygen gas (O2)?
They are bonded by a double covalent bond.
Which of the following is not a result of hydrogen bonds?
Two hydrogen atoms join together to form a molecule of hydrogen gas.
Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not?
Yes, because they can become more stable by doing so.
What is an ion?
an atom that has either gained or lost electron(s)
What holds the sodium and chloride ions together in a chemical bond?
an electrical attraction between opposite charges
Which of the following would represent the attraction between an anion and a cation?
an ionic bond
Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest?
covalent, ionic, hydrogen
How many hydrogen atoms will a single carbon atom bond with to form a stable molecule?
four
How many valence shell electrons does the element carbon have?
four
Chemical reactions proceed more quickly at ______
higher temperature
What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?
hydrogen bond
Covalent bonds:
involve the sharing of one to three pairs of electrons.
Which type of bond would most likely form between lithium and fluorine to make lithium fluoride?
ionic bond
Salts are always ________.
ionic compounds
What does this figure depict?
ionization, followed by ionic bonding
Bonds between carbon and hydrogen atoms (as depicted on the right side of the figure) are generally __________.
nonpolar covalent bonds
Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell?
one
A molecule of water (H2O) is formed by what type of bond?
polar covalent bonds
Formation of hydrogen bonds requires hydrogen atoms and what else?
polar covalent bonds
Amino acids joining together to make a peptide is a good example of a(n) ________ reaction.
synthesis
Hydrogen bonds would be found in which of the following?
the complex, three-dimensional structure of protein molecules
The reactivity of an atom is based on _________
the number of electrons in its outer valance
When an ionic bond forms, which part(s) of the atoms are directly involved?
the outermost electrons
A chemical reaction in which bonds are broken is usually associated with ________.
the release of energy
What is the most significant factor in the formation of a covalent bond?
the sharing of electron pairs between two atoms
One carbon atom can combine with two oxygen atoms to form carbon dioxide. Use the diagram to predict the type of bond that would be necessary to join the oxygens to the carbon to form a stable molecule.
two double bonds
Which parts of atoms can interact (react) to form chemical bonds?
valence electrons
The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom?
2, 8, 1
Define polar covalent bond
A bond in which electrons are shared unequally.
Which of the following is not produced through chemical bonding?
atoms
ATP → ADP + Pi is an example of a(n) ________ reaction.
decomposition
