Atoms with the same number of protons but with different electrical charges _.
Are different ions.
In salt, what is the nature of the bond between sodium and chlorine?
Ionic
What is the result of the animated process?
A positively charged sodium ion and a negatively charged chlorine ion.
An ionic bond involves _.
An attraction between ions of opposite charge.
Which of these figures correctly illustrates the nature of the bonding of H2O?
What type of bond joins the carbon atom to each of the hydrogen atoms?
Single (nonpolar) covalent
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
6
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes.
Fluorine’s atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
10
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
5
What is the term for an atom that is electrically charged as a result of gaining or losing electrons?
ion
The brackets are indicating a(n) _ bond
Hydrogen
What name is given to the bond between water molecules?
Hydrogen
Each water molecule is joined to _ other water molecules by bonds.
four ……. hydrogen
The unequal sharing of electrons within a water molecule makes the water molecule _.
polar
What type of bond is joining the two hydrogen atoms?
a. covalent
b. hydrophobic
c. hydrophilic
d. ionic
e. hydrogen
a. covalent
A(n) _ refers to two or more atoms held together by covalent bonds.
a. community
b. ion
c. isotope
d. shell
e. molecule
e. molecule
This atom can form up to _ single covalent bond(s).
a. 0
b. 3
c. 2
d. 1
e. 4
e. 4
A(n) _ bond joins these two oxygen atoms.
a. ionic
b. hydrogen
c. double covalent
d. single covalent
e. quadruple covalent
c. double covalent
The brackets are indicating a(n) _ bond.
a. polar covalent
b. hydrogen
c. ionic
d. hydrophobic
e. single (nonpolar) covalent
b. hydrogen
What name is given to the bond between water molecules?
a. hydrogen
b. ionic
c. single (nonpolar) covalent
d. hydrophobic
e. polar covalent
a. hydrogen
Atoms with the same number of protons but with different electrical charges _.
a. have different atomic numbers
b. are different isotopes
c. are different ions
d. have different atomic masses
e. have different numbers of neutrons
c. are different ions
In salt, what is the nature of the bond between sodium and chlorine?
a. ionic
b. hydrogen
c. hydrophobic
d. polar covalent
e. nonpolar covalent
a. ionic
What is the result of the animated process?
a. a negatively charged sodium ion and a positively charged chlorine ion
b. a negatively charged sodium ion and a negatively charged chlorine ion
c. covalent bond formation
d. a positively charged sodium ion and a positively charged chlorine ion
e. a positively charged sodium ion and a negatively charged chlorine ion
e. a positively charged sodium ion and a negatively charged chlorine ion
An ionic bond involves _.
a. water avoidance
b. the unequal sharing of an electron pair
c. no atoms other than sodium and chlorine
d. the sharing of a single pair of electrons
e. an attraction between ions of opposite charge
e. an attraction between ions of opposite charge
What type of bond joins the carbon atom to each of the hydrogen atoms?
a. polar covalent
b. single (nonpolar) covalent
c. double (nonpolar) covalent
d. hydrogen
e. ionic
b. single (nonpolar) covalent
The tendency of an atom to pull electrons toward itself is referred to as its _.
electronegativity
In this molecule, what type of bond is found between the oxygen and hydrogens?
polar covalent
Which of these bonds is weakest?
Why isn’t this insect drowning?
Surface tension
A phrase that applies to covalent bonding and not other kinds of bonds is …
electron-sharing
The term for a solution with a low pH number, such as lemon juice or vinegar, is
acidic
The term for a solution that has an equal concentration of H+ and OH- is
neutral
The term for a solution with a high pH number, such as ammonia or bleach, is
basic
An acid is a compound that donates __ to a solution.
H+
The higher the pH number, the higher the concentration of _ in a solution.
OH-
A substance that accepts H+ when they are in excess and donates H+ when their concentration drops is called a(n) __.
buffer
The tendency of water molecules to stick together is called __.
cohesion
What is the pH inside most living cells?
pH 7
Silicon has an atomic number of 14 and a mass number of 28. How many neutrons are found in silicon?
14
Carbon-12 and carbon-13 are different in the number of their _.
neutrons
Four elements combine to make about 96% of the mass of the human body. Which of the following elements is one of the four?
carbon
An atom’s __ are found in its nucleus.
neutrons and protons
The four most common elements found in living organisms are __.
carbon, oxygen, nitrogen, and hydrogen
The bond between oppositely charged ions is a(n) __ bond.
ionic
What name is given to bonds that involve the sharing of electrons?
covalent
Adjacent water molecules are joined by __ bonds.
hydrogen
Sweating cools your body by __.
evaporative cooling
As water freezes, __.
its molecules move farther apart
What does the term electron orbital describe?
a. An electron orbital describes the exact distance of an electron from the nucleus.
b. An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.
c. An electron orbital describes the orbit of an electron around the nucleus.
b. An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.
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What happens when two atoms form a chemical bond?
a. A chemical bond forms when two atoms transfer or share protons to achieve a stable nucleus.
b. Two atoms fuse together to form a chemical bond.
c. A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells.
c. A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells.
In the term trace element, the adjective trace means that
a. the element is very rare on Earth.
b. the element can be used as a label to trace atoms through an organism’s metabolism.
c. the element is required in very small amounts.
d. the element passes rapidly through the organism.
e. the element enhances health but is not essential for the organism’s long-term survival.
c. the element is required in very small amounts.
Compared with 31P, the radioactive isotope 32P has
a. a different atomic number.
b. a different charge.
c. one more neutron.
d. one more proton.
e. one more electron.
c. one more neutron.
Which statement is true of all atoms that are anions?
a. The atom has more neutrons than protons.
b. The atom has more protons than electrons.
c. The atom has fewer protons than does a neutral atom of the same element.
d. The net charge is 1-.
e. The atom has more electrons than protons.
e. The atom has more electrons than protons.
Which of the following statements correctly describes any chemical reaction that has reached equilibrium?
a. The reaction is now irreversible.
b. Both forward and reverse reactions have halted.
c. The rates of the forward and reverse reactions are equal.
d. The concentrations of products and reactants are equal.
e. No reactants remain.
c. The rates of the forward and reverse reactions are equal.
The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound.
a. HS
b. H3S2
c. H4S
d. HS2
e. H2S
e. H2S
Which statement about weak bonds is correct?
a. Weak bonds are transient and easily reversible.
b. Weak chemical bonds form only between atoms of similar electronegativity.
c. Weak bonds are less important to living things than strong covalent bonds.
a. Weak bonds are transient and easily reversible.
