Elements and Atoms - AP Chemistry

Ionic bonds occur between metals and non-metals. The non-metal species are often halogens, very electronegative atoms which will completely take one of the non-metal's electrons. An ionic bond is not as much a bond as it is an association between positive and negatively charged atoms (ions). This association leads to the formation of rigid lattice structures of ionic compounds. Which makes them very stable, as seen by their high boiling points. When looking for ionic bonding, look for bonding between non-metals and metals, and atoms that are from opposite ends of the periodic table.

Atoms in the third period and above have d-orbitals that can hold up to 10 elecrons. This is what allows for atoms to exceed the octet rule.

B (boron) is one of the atoms known for making fewer than 4 covalent bonds, and therefore not filling its octet. C (carbon) always makes 4 bonds, while O (oxygen) and Cl (chloride) are also known for having full octets.

Rust forms when a substance is oxidized; thus iron cannot be a better oxidizing agent, because that would mean it would be more easily reduced. Aluminum and zinc are reactive, so that answer choice can be ruled out. Aluminum and zinc can form protective oxides by complexing the atom with oxygen.

While many transition metals will lose an electron from the s shell before the d shell, many transition metals will lose only one electron from the s shell or none at all. The reason for this is that there is an enhanced stability when the transition metal's d shell is half filled, , so trasition metals will lose or not lose from the s shell in order to obtain a more stable electron configuration.

Electronegativity is defined as the tendency of an atom to attract an electron in a bond that it shares with another atom. Because oxygen wants to receive two elctrons, while both sodiums wish to lose one electron, oxygen has a higher electronegativity than sodium. Typically, electronegativity can be seen as increasing as you go to the top right of the periodic table. For example, fluorine has a higher electronegativity than nitrogen.

Strontium is in the same group as calcium in the periodic table, which means that they both have the same number of valence electrons; they are both alkaline earth metals with two valence electrons. This is one of the most important chemical properties, as it dictates how an element will react. Like calcium, strontium will lose its two valence electrons easily to form ionic compounds.

Metals are on the left side of the periodic table, nonmetals on the right, and metalloids follow a diagonal line from boron down to polonium. Silicon is one of these.

In general, metallic character decreases from the left of the period to the right, with the far right of the table representing the noble gases. Metalloids represent the junction between the metals and nonmetals within the period.

Metallic compounds have unique properties due to their electron motility. In metals, electrons are able to move freely around and between atoms. In non-metals, electrons are more tightly bound to the nucleus due to increased nuclear positive charge and decreased atomic radius. The fluidity of electrons in metals allows them to conduct electric charge.

Metals are generally non-brittle. Metals are solids at room temperature and conduct electricity in the liquid phase, but they share these properties with a number of non-metal compounds as well.

The chemistry of elements in a group are the most similar due to their valence electron configuration being identical. Both phosphorus and arsenic have 5 valence electrons, therefore, is most chemically similar to . Phosphate is the polyatomic ion .

First, we have to remember that the more negative the electron affinity (EA) is, the easiest will be for an atom to grab an extra electron. A positive EA means that we have to supply an atom with energy for it to accept an extra electron. The general trend of EA is to increases from bottom to top in a group and from left to right in a period. Hence, sodium is on top of potassium it should have larger affinity. However, calcium has a smaller EA than potassium. Elements of the group 2A do not follow the general trend. They have a semi-closed shell electronic structure with paired electrons in the outermost s orbitals. Such structure requires extra energy to be broken.

In this question, we're asked to determine a period trend. Specifically, we're asked to determine which answer choice increases as one moves down the periodic table.

Electronegativity describes the pull an atom has on the electrons shared in a covalent bond. The greater the effective nuclear charge, the greater the attraction these electrons will have for the positively charged nucleus. When moving from left to right on the table, electronegativity increases. Also, moving from bottom to top on the table corresponds to an increase in electronegativity.

The trend in electron affinity is similar to the trend in electronegativity for much the same reasons. Electron affinity describes how willing an atom is to accept an additional electron. When this happens, a certain amount of energy is released. The more energy that is released, the more stable that atom has become. Electron affinity increases as one moves from left to right on the table, and also when one moves from top to bottom.

Ionization energy is the amount of energy that is needed in order to remove an electron from an atom or ion. Once again, for much the same reasons as discussed above, the trend of ionization energy will increase when moving from left to right across the periodic table, and also when moving from bottom to top.

Lastly, let's consider atomic radius. This term describes roughly the distance between the center of an atom and its outer electron shell. As we move from left to the right, the effective nuclear charge increases as each atom gains an additional proton (a more positively charged nucleus will exert a greater pull on the outer electrons, causing the radius to decrease). Also, as we move down the periodic table, additional energy shells (energy levels) are added. Since each subsequent shell represents valence electrons that are farther away from the nucleus, the radius of the atom increases. Thus, as we move down the table, atomic radius is the property that is expected to increase.

Hydrogen has an atomic mass of 1.009 amu, which implies that is the predominant isotope. Neutral hydrogen has an equal number of protons as electrons, which is 1 each. While hydrogen can behave as an alkali metal or as a halogen by losing or gaining an electron to attain a full valence shell, it does not exhibit properties of metals, which are electrically and thermally conductive. Thus the location of hydrogen on the periodic table may be misleading, since it is a nonmetal.

Atomic radius increases down the columns and to the left. The furthest left elements are Na and Cs. Cs is furthest down so it is the biggest.

If we look at elements of the same period the prinicipal quantum number for each one of these elements is the same. Thus the outermost energy level for the electrons of each atom is the same. If we consider moving through the periodic table in numerical order, the left side of the periodic table features atoms that have just begun to add electrons to new energy levels. On the right side of the periodic table the elements are moving closer to filling the energy level. The differences in atomic radii are the result of differing amounts of protons between atoms whose electrons are in the same energy level. K has one electron in the fouth energy level and Kr has eight electrons in the fouth energy level. K has 19 protons with which to generate pull on the electrons. Kr has 36 protons with which to generate pull on the electrons. Thus Kr has a smaller atomic radius becasue of its ability to have a tighter grasp on its electrons becasue of the stronger charge generated by its nucleus.

Electronegativity measures the ability an atom to attract shared electrons
in bond. It follows a trend that it increases moving from left to right and down to up across
the periodic table.

The trend for radius is that it increases down and to the left

Atomic radius decreases as one moves across the periodic table from left to right, since effective nuclear charge increases and the electrons are held more tightly to the nucleus.

The alkali metals are found in the first group (column) of the periodic table, on the leftmost side. They have only 1 loosely bound electron in their outermost shells, and their effective nuclear charge values are low, giving them the largest atomic radii of all the elements in their periods.

The transition metals are capable of losing various numbers of electrons from the s and d orbitals of the valence shell. Metals such as Cu, Fe, and Mn have various oxidation states and can form many different ionic compounds.