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The Basic Building Blocks of Matter
Although atoms make up matter, we cannot see them because they are quite small. Indeed, in the dot of an "i" on this page, there are approximately a billion atoms! Atoms cannot be seen with a microscope. |
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| Anything that has mass and takes up space. |
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| Protons, Neutrons and Electrons |
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Small, spherical particles that are arranged in a very specific way to form an atom.
Protons and neutrons clump together in the nucleus of the atom. Electrons whirl around in an orbit outside of the nucleus. |
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| In an atom, the nucleus refers to the center of the atom where the protons and neutrons clump together. |
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An explanation or representation of something that cannot be seen.
We don't really know what atoms look like, because they are too small to see, even under a microscope. However, scientists have done many experiments designed to help us understand their structure, and have created models that are consistent with those experiments. |
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| What determines all of an atom's properties? |
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| All of an atom's properties are determined by the number of electrons, protons, and neutrons that it contains. The vast majority of an atom's properties, however, are determined by the number of electrons (or protons) that an atom has. |
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A collection of atoms that all have the same number of protons.
Since the number of electrons (and therefore the number of protons) is the most important factor in determining an atom's properties, we tend to separate atoms by their number of protons. Atoms that have the same number of protons (regardless of their number of neutrons) are said to belong to the same element. |
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Carbon (Carbon contains all atoms that have 6 protons and 6 electrons).
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Hydrogen
Hydrogen is made up of all atoms that have 1 proton and 1 electron.
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Oxygen
Oxygen contains all atoms that have 8 protons and 8 electrons.
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Nitrogen
Nitrogen contains the atoms that have 7 protons and 7 electrons.
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Phosphorous
Phosphorus contains those atoms with 15 protons and 15 electrons.
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Sulfur
Sulfur is made up of the atoms that have 16 protons and 16 electrons.
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When different atoms have the same number of protons, they are said to belong to the same element, because they have the same basic properties.
To make an atom, we call it by the element to which it belongs, followed by the sum of its protons and neutrons. Thus, when you see a name like sulfur-32, thou know that we are talking about a particular atom, the one that has 16 protons and 16 neutrons.
On the other hand, if you see just the name sulfur (S), then you know that we are talking about an element, which probably contains more than one type of atom. After all, there are several atoms that all have 16 protons and thus belong to the element sulfur but have different numbers of neutrons. |
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| Two atoms have slightly different properties, but they belong to the same element. What is different about them: their numbers of protons, neutrons, or electrons? |
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| Atoms that belong to the same element have the same number of protons and therefore the same number of electrons as well. Thus, their numbers of neutrons are different. |
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| Number of known elements in God's creation? |
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Chemicals that result from atoms linking together.
For example, carbon dioxide is a gas that humans produce as a part of their metabolism. This gas is formed when 1 carbon and 2 oxygens link together. |
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| Molecules have abbreviations, just like elements. CO2, for example is Carbon Dioxide. The C stands for carbon and the O for oxygen. Numbers that appear as subscripts indicate how many of those atoms are in the molecule. If no subscript appears after an element, we know that there is only 1 atom of that type in the molecule. So CO2, has One Carbon, and two Oxygen atoms. |
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A change that affects the appearance but no the chemical makeup of a substance.
Suppose you mix sugar and water. The sugar would dissolve into the water. The sugar is still there, the water is still there, but they are now mixed. Their molecules have not changed, they have just been mixed together. That is a physical change. |
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A change that alters the makeup of the elements or molecules of a substance.
Suppose you took a piece of paper and lit it with a match? The paper would burn making flames and smoke appear. A pile of ashes would be left where the paper was once. That is a chemical change. |
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| are generally not reversible |
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| The first important type of physical change involves the phases of matter. |
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| Phase: one of three forms - solid, liquid, or gas (which every substance is capable of attaining). |
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Phases in Physical Change
Solid - Liquid - Gas |
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Cooling a substance down (freezing it) changes something from its liquid phase to its solid phase. When you cool a substance, it removes energy from the molecules of the substance.
To change a substance from its solid phase to its liquid phase, we simply have to melt it. This involves heating it up. When you heat a substance up, you are, in fact, adding energy to its molecules.
Changing the phase of a substance is really just a matter of modifying the energy that the molecules of the substance have. If you take energy away from the molecules of a substance, the phase of the substance changes from gas to liquid to solid. If you add energy to a substance, the phase of the substance changes from solid to liquid to gas. The chemical makeup of the molecules does not change. These changes are physical changes. |
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One type of physical change. It occurs when one substance is dissolved in another. The result is called a solution.The substance being dissolved in the liquid is called the solute, and the liquid is called the solvent.
In the case of salt being dissolved in water, the solute is salt, the solvent is water and the resulting solution is salt water. |
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The random motion of molecules from an area of high concentration to an area of low concentration.
Molecules that are in their liquid phase and molecules that are dissolved in liquid tend to move about randomly as a matter of course.
Both the solvent and solute can randomly flow through the membrane. Since random motion tends to even things out, the net result is that solute molecules flow from the side of high concentration tot he side of low concentration. |
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| A measurement of how much solute exists within a certain volume of solvent. |
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| A membrane that allows some molecules to pass through but does not allow other molecules to pass through. |
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The tendency of a solvent to travel across a semipermeable membrane into areas of higher solute concentration.
In osmosis, only the solvent can flow through the membrane. As a result, the attraction that the solvent feels for the solute pulls solvent across the membrane into the side with the most solute. This evens out the concentration of solute. |
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| A substance that alters the speed of a chemical reaction but is not used up in the process. |
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| A molecule that contains only carbon and any of the following: hydrogen, oxygen, nitrogen, sulfur and/or phosphorous. |
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The process by which living organisms produce larger molecules from smaller ones.
Photosynthesis is an example of biosynthesis. Living organisms, like plants, take small molecules like CO2 and H2O and make a large molecule like glucose. That's biosynthesis. |
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| organic molecules that contain only carbon hydrogen and oxygen. In addition, they have the same ratio of hydrogen atoms to oxygen atoms as does water. |
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| gives the type and number of atoms in the molecule, but also tells which atoms are linked to which. |
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| Two different molecules that have the same chemical formula. Different molecules have different chemical properties. |
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| Chemical Formula of Fructose and Glucose |
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C6H12O6 - identical, and yet while they have the same chemical formula, they have different structural formulas.
These different structural formulas are the reasons behind the taste difference and other chemical differences between glucose and fructose. |
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Simple carbohydrates that contain 3 to 10 carbon atoms.
The reason that these are called monosaccharides is that they form the bass building blocks of more complex carbohydrates called disaccharides and polysaccharides. |
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Carbohydrates that are made up of two monosaccharides.
Disaccharides and Polysaccharides form the basis of much of the food that we eat. |
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| Carbohydrates that are are up of more than two monosaccharides. |
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A Chemical reaction in which molecules combine by removing water.
For example, table sugar is a disaccharide called sucrose. It is formed when glucose and fructose chemically react in a process known as a dehydration reaction.
When you dehydrate something, you remove water. |
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| Breaking down complex molecules by the chemical addition of water. Hydrolysis is the reverse of dehydration. |
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A class of molecules that contain the following pattern of atoms bonded together. When a molecule has a section that looks like the one below, it is often called an acid group.
O
II
-C-OH
In general, acids are substances that taste sour. |
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| Organic bases have a group of atoms in common, which is often called the amine group. |
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| a solution that has a pH of 7 |
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| a solution that has a pH from 0 to 7 is acidic. The lower the pH, the stronger the acidic nature of the solution. |
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| a solution with a pH from just above 7 to 14 are called alkaline and have the characteristics of a base. The higher the pH, the more like a base the solution becomes. |
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Also known as fats, these are complex molecules formed when three fatty aids, link to a substance known as glycerol in a dehydrate reaction.
Lipids are important biologically because most animals store most of their excess food as lipids.
Twice the amount of energy can be stored in an ounce of fat as can be stores in an ounce of carbohydrates. |
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Lacking any affinity to water.
Lipids are not attracted to water, and simply cannot be dissolved in it. |
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| A lipid made from fatty acids that have no double bonds between carbon atoms. |
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| A lipid made from fatty acids that have at least one double bond between carbon atoms. |
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| How do you know whether a fat is saturated or unsaturated? |
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One way is to look at the structural formula of the fat. If there are double bonds between the carbons in the fatty acids, it is an unsaturated fat. Otherwise it is saturated.
There is another way to distinguish these two types of fats. You can look at their phase. At room temp, saturated fats tend to be solid while unsaturated fats tend to be liquid. |
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| Make up one of the most important groups of molecules in the chemistry of life. They are involved in virtually every chemical reaction that supports life. They come in many shapes and sizes and are very complex. They are mostly made from carbon, nitrogen, hydrogen, and oxygen, but some proteins have phosphorous and sulfur in them as well. |
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The basic building blocks of a protein. There are about 20 different amino acids in the proteins that make up life, and the type of amino acid along with the order in which the amino acids are linked up determine reactions.
Amino acids are linked dehydration reactions, just like monosaccharides do when they link up to form polysaccharides. |
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A bond that links amino acids together in a protein.
As amino acids link together, ejecting water, a bond called a peptide bond forms. |
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| A strong attraction between hydrogen atoms and certain other atoms (usually oxygen or nitrogen) in specific molecules |
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| An atom must have the same number of what? Protons, neutrons, electrons? |
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| Atoms must have the same number of protons as electrons. |
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| The element sulfur is comprised of all atoms that have 16 protons. How many neutrons are in Sulfur-34? |
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| The number after the element name tells you the total number of neutrons and protons in the nucleus. If there are 16 protons, there use be 18 neutrons for the total to add to 34. |
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| Is P an atom, element or molecule? |
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| This is an element, as there is only one symbol and no number following the symbol. |
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| Is N2 an atom, element or molecule? |
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| This is a molecule, since two elements are present. |
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| Is oxygen-16 an atom, element or molecule? |
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| This is a specific atom, since the name of the element and the total number of neutrons and protons in the nucleus are both given. |
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| Is PH3 an atom, element or molecule? |
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| This is a molecule, as it is composed of two elements (P and H) |
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| When you mix sugar in water, is that a physical or chemical change? |
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| What four things are necessary for photosynthesis? |
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| carbon dioxide, water, energy from sunlight and a catalyst. |
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| In a carbohydrate, what is the ratio of H's to O's? |
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| 2:1. If there are two O's, there must be four H's. |
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| Is a solution with a pH of 1.5 acidic? |
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| Yes, The pH scale says that pH's below 7 are acidic. The lower the pH, the more acidic. |
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| What part of the nucleotide is responsible for the way DNA stores its information? |
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| The nucleotides base is what determines the "Morse code" of DNA. |
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| What is hydrogen bonding, and what part does it play in DNA? |
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| Hydrogen bonding between the bases holds DNA's double helix together. |
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a special class of proteins that at as catalysts for many of the chemical reactions that support life.
For example, in order to digest disaccharides and polysaccharides, animals must break them down into monosaccharides using hydrolysis. But hydrolysis reactions are incredibly slow, and animals would die long before they could digest polysaccharides if it weren't for enzymes. These proteins are catalysts for the hydrolysis reactions, making them fast enough to allow the proper digestion of food. |
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