Integrated Physical Science chapter 9 & 10
The element sodium (Na) has how many valence electrons?
1
A solute is
b. the material that dissolves in the solvent portion of a solution. Correct
A chemical equation is balanced by changing (the)
coefficients
A polar molecule has a positive and a negative side or end.
TRUE
The solubility of a gas in water decreases as the water temperature increases.
TRUE
Water containing large amounts of Mg2+ and Ca2+ ions is said to be hard because it is hard to make soap lather in the water.
TRUE
List 3 materials (not chemical compounds!) that contain hydrogen bonds.
The correct answer is: proteins, DNA, spiderwebs, cellulose, water, nylon
What effect does temperature have on Reaction Rates?
a. Higher temperatures tend to increase reaction rates. Correctcorrect
Why is the salinity of seawater increased when it freezes?
a. The ice that is formed is essentially pure water so there is less water in solution. Correctcorrect answer
Hydrogen and oxygen are combined to form water. What term best describes this process?
a. chemical change Correctcorrect
What type of reaction has the general form AX + BY → AY + BX.
a. ion exchange Correctcorrect answer
If the force of attraction between the ions in a solid is very strong, you would expect the solid to have
a. low solubility in water. Correct
The outer electrons of metal atoms differ from the outer electrons of nonmetal atoms in that the outer electrons of metals
all of above
Why does ice, the solid form of water, float?
b. It floats because it is less dense than water because of the open spaces between molecules produced by its hexagonal structure.
According to the definition of acids and bases, NH3 is
b. a base because it can accept H+ ions from water.
The heat of fusion, specific heat, and heat of vaporization of water are high compared to similar substances such as hydrogen sulfide, H2S, because
b. hydrogen bonds form between water molecules. Correct
Metallic bonds create materials with properties that make them
b. malleable and good conductors of electricity. Correctcorrect
To say a chemical equation is balanced means the
b. number of times each element appears as a reactant is equal to the number of times it appears as a product
The terms 'ionic, covalent, and metallic' represent
b. three ways atoms in a molecule can have relationships with their electrons. Correctcorrect
Which of the following are properties of basic solutions?
c. They feel slippery. Correct
To see an everyday example of oxidation-reduction, you might observe
c. a car rusting. Correctcorrect
A hydrogen bond is
c. a force between the hydrogen atom of one polar molecule and another polar molecule. Correct
A solution has a pH of 9. This means that the solution is
c. basic. Correct
Which of the following terms best describes a well mixed cup of coffee with sugar?
c. homogeneous mixture Correctcorrect
Chemical energy is stored within molecules as
c. internal potential energy. Correctcorrect
Covalent bonds and ionic bonds differ in that
c. ionic bonds don't involve the sharing of electrons Correctcorrect
Chemical bonds are
c. the redistribution of electrons between atoms, leading to a more stable configuration. Correctcorrect
The electrons in the outer level of the atom are called
c. valence electrons. Correctcorrect
in liquid solutions, the solute is
d all of these could be true
Select the best description of an element.
d. A pure substance that cannot be broken down into anything simpler by chemical or physical means. Correctcorrect
Which of the following are properties of acidic solutions?
d. All of these are true. Correct
What elements tend to form ionic compounds?
d. Elements found on opposite sides of the periodic table.
What is the difference between a compound and a mixture?
d. The components of a mixture are not chemically bonded together Correctcorrect
Hydrogen bonding in water accounts for
d. all of these are true. Correct
Covalent bonds are formed when
d. atoms share electrons. Correctcorrect
A solution with a pH of 2
d. is one tenth as acidic as a solution with a pH of 1.
Which makes the best electrical conductor?
d. metallic bonds. Correctcorrect
Acid rain
d. occurs when nitrogen oxides undergo gas-phase reactions producing nitric acid.
The modern definition of an acid is any substance
d. that is a proton donor. Correctcorrect answer
Which statement is true of oxidation-reduction reactions?
e. All of the above are true. Correctcorrect
Water solutions of ionic substances that conduct electricity are called
electrolytes
Salt is spread on icy roads because it
lowers the freezing point of water.
What is a particle composed of two or more atoms held together by an attractive force called?
molecule
Air is considered to be a homogeneous mixture that is 79% nitrogen gas, 20% oxygen gas and 1% all the other gases. In this mixture, nitrogen can be considered
solvent
The presence of solute molecules makes a solution freeze at a lower temperature than the pure solvent.
true