| A | B |
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| Acidic solutions have a pH that is ____ seven. | below |
| Basic solutions have a pH that is ___ seven. | above |
| Distilled water has a pH of ___. | seven |
| A liquid with a pH of 1 would be described as being ___. | strongly acidic |
| A liquid with a pH of 6 would be described as being ___. | weakly acidic |
| A liquid with a pH of 8 would be described as being ___. | weakly basic |
| A liquid with a pH of 13 would be described as being ___. | strongly basic |
| A compound held together by covalent bonds is called a(n) ___. | molecule |
| Atoms or molecules that become charged because they gain or lose electrons are called ___. | ions |
| A negatively charged ion would be ____ by another negatively charged ion. | repelled |
| A positively charged ion would be ____ by another positively charged ion. | repelled |
| A negatively charged ion would be ___ by a positively charged ion. | attracted |
| Two types of compounds are ____ and ____. | molecules and ionic compounds. |
| Electrons gain potential energy when they move ____ from the nucleus. | away |
| When an electron falls back toward the nucleus, energy is ___. | released (or lost) |
| When electrons lose energy (by falling back toward the nucleus), the lost energy is usually released to the environment in the form of ___. | heat |
| The first electron shell of an atom can hold no more than ___ electrons. | two |
| The second electron shell of an atom can hold no more than ___ electrons. | eight |
| The chemical behavior of an element depends mostly on ____. | the number of electrons in its outermost shell |
| Electrons in the outermost shell of an atom are called ____. | valence electrons |
| The outermost shell of an atom is called the ___. | valence shell |
| An atom with a full valence shell of electrons is chemically _____ (a.k.a. _____) | unreactive, inert |
| In _____ bonds, pairs of electrons are shared between two or more atoms. | covalent p. 38 |
| Single covalent bonds share ___ pair(s) of electrons. | one pair (two electrons total) |
| Double covalent bonds share ___ pair(s) of electrons. | two pairs (4 electrons total) |
| Triple covalent bonds share ___ pair(s) of electrons between the two atoms involved. | three pairs (6 electrons total) |
| Draw the electron distribution diagram for a molecule of oxygen being held together with a double covalent bond. |  |
| Compounds formed by ionic bonds are called ____ . | ionic compounds |
The picture below shows the formation of a(n) _____ bond.,  | ionic, |
| A chemical reaction in which arrows are pointing both ways is said to be ____. | reversible |
| A weak attraction between hydrogen in one molecule and either an oxygen or nitrogen atom in another molecule is called a(n) _____. | hydrogen bond |
| Distilled water has a pH of ___. | seven |
| Bonds in which the electrons between two atoms are shared about equally are called _____. | nonpolar covalent bonds |
| Bonds in which the electrons between two atoms are not SHARED equally (because one atom's nucleus has a much stronger attraction for electrons) are called _____. | polar covalent bond |
| Bonds in which electrons aren't shared at all (because one atom just steals one or more electrons from another atom) are called ______ bonds. | ionic |
| A weak attraction between hydrogen in one molecule and either an oxygen or nitrogen atom in another molecule is called a(n) _____. | hydrogen bond |
| Which side of a water molecule has a partial positive charge and which side has a partial negative charge? | Oxygen side has a partial negative charge and the hydrogen end has a partial positive charge. |
| Molecules in which the overall charge is unequally distributed, leading to parts of the molecule having a partial positive charge while other parts have a partial negative charge (like water) are called ______. | polar molecules |
Why is it unlikely that two neighboring water molecules would arrange themselves like the ones shown below?,  | The hydrogen ends of each water molecule both have a partial positive charge, and therefore would repel each other, making it unlikely that they would be arranged like the picture below shows., |
| The fact that water molecules are attracted to each other is an example of ____. | cohesion,  |
| The ability to pour water into a glass past the top of the glass, water forming drops that stick together, and waterbugs not falling through the surface of a pond can be explained by the phenomenon of _____. | cohesion (Water is pretty cohesive because it is a polar molecule so the positive end of one water molecule are attracted to the negative ends of other water molecules. These attractions BETWEEN water molecules are caused by the formation of hydrogen bonds), |
| The attraction of water molecules to the surfaces of some materials is called _____. | adhesion (Adhesion between water molecules and the glass in the graduated cylinder are responsible for the upward pull of water molecules along the sides, known as a meniscus. Specifically, the glass just above the water line is also attracting water molecules, so the water is pulled upward. This is also how capillary action works.) p.48,  |
| The meniscus observed in a graduated cylinder full of water is caused by the ____ of water to the molecules that make up the glass in the cylinder., | adhesion, |
| Pure water freezes at ___ Celsius and boils at ___ Celsius. | 0, 100 p.48 |
| The ____ of a substance is defined as the amount of heat (energy) that must be absorbed or lost by a substance to change its temperature by 1 degree Celsius. | specific heat (In the graph below, it shows that the specific heat is 1cal/C for the liquid phase of water. This is represented by the gentle upwardly sloping part of the graph between 0 and 100C) p.48,  |
| Compared with most other substances, water has an unusually high ____ which explains why it can store a lot of energy and it takes a lot of energy to change its temperature. | specific heat |
| Why doesn't it get really cold or really hot when you are out at sea? | The high specific heat of water allows it to absorb a lot of heat from the air without increasing its own temperature too much. When cold air blows over the ocean, the large amount of heat (not to be confused with temperature) can be transferred to the air. Since air has a much lower specific heat, it will warm up easily. In places like the Bering Sea of Alaska, the ocean water keeps the air from getting too much below 20 degrees Fahrenheit even in the middle of winter. In summer, it keeps the air from getting too much above 55 degrees F.,  |
| The transformation from a liquid to a gas is called ____ or ____. | evaporation (Or vaporization. Boiling is the temperature at which the average molecule has enough energy to overcome the attractions that hold molecules together as a liquid. Therefore, the molecules vaporize quite quickly once the boiling point has been reached) |
| Water helps moderate Earth's temperature by _____ a lot of heat to become water vapor at the equator and then the moist air moves toward the poles to ____ that heat as the water vapor _________ | absorbing, release, condenses (When water evaporates, it uses a lot of energy to break the hydrogen bonds that keep the water molecules near each other in liquid form. When the water vapor condenses, a lot of heat energy is released as a bunch of new hydrogen bonds form),  |
| The _____ of water from humans and other organisms helps keep them cool. | evaporation (It does this because heat energy from the body is used to break the hydrogen bonds between water molecules that make up most of your sweat. Since this heat energy is being used to break those hydrogen bonds, your body loses heat, and you stay cooler) |
| Water reaches its greatest density at ___ degrees Celsius. | 4 (So in a cold lake in the winter where the warmest water is 4 degrees Celsius, the warmest water would be found at the bottom of the lake and the coldest at the top. In the summer, the opposite happens. Water gets colder as you go deeper.),  |
| If ice didn't float, lakes and oceans would ______. | eventually freeze solid because ice would sink, exposing liquid water at the surface to cold winter temperatures and wind instead of insulating it from the cold temperatures. |
| The type of substances that dissolve best in water are ____. | ionic substances and polar molecules |
| Any substance that is attracted to water is said to be ____. | hydrophilic (hydro = water, philic = loving) |
| Any substance that is not attracted by water is said to be ____. | hydrophobic (hydro = water, phobic = fearing) |
Which type of bond is represented by the dotted line? By the straight line inside the water molecule?,  | Dotted lines = hydrogen bonds, straight lines = covalent bonds p.47, |
| If the concentration of hydrogen ions in a solution is higher than the concentration of hydroxide ions, the solution will be ____. | acidic |
The substance shown below is a(n) ____ and an increase in its concentration will cause a(n) ___ in pH.,  | hydrogen ion, drop in pH (to become more acidic), |
The substance shown below is a(n) ____ and an increase in its concentration will cause a(n) ___ in pH.,  | hydroxide ion, increase in pH (to become more basic) |
.,  | strong acids,  |
.,  | strong bases |
.,  | weak acids, |
.,  | weak bases, |
| The pH scale is kind of like the richter scale (for earthquakes) in that a change of one (such as going from pH 4 to pH 3) represents a ___-fold change in hydrogen ion concentration. | 10-fold change (for example, pH 3 is 10 times more acidic than pH 4) |
| The binding together of like molecules, often by hydrogen bonds, is called ____. | cohesion,  |
| A substance that reduces the hydrogen ion concentration of a solution is called a(n) ___. | base |
| The attraction between DIFFERENT kinds of substances is called ____. | adhesion (Adhesion between water molecules and the glass in the graduated cylinder is responsible for the upward pull of water molecules along the sides, known as a meniscus. Specifically, the glass just above the water line is also attracting water molecules, so the water is pulled upward. This is also how capillary action works.), |
| A measure of how difficult it is to break or stretch the surface of a liquid is called ___. | surface tension (This is responsible for the ability of the water strider in the picture below to stay on the surface of the water and is due to the hydrogen bonds that attract water molecules to each other),  |
| What does the root word "philic-" mean? | loving (Philia means loving. Hydro means water. Hydrophilic means water loving) |
| What does the root word "phobic-" mean? | fearing (Phobia means fear. Hydro means water. Hydrophobic means water fearing) |
