Atoms and Elements - College Chemistry

The normal electron configuration for is as follows:

Since it is losing electrons, the element must lose the electrons from the highest energy shell first. Thus, the element loses electrons from and electron for .

The electron configuration for is then

Start by finding the noble gas core. For iron, this will be argon as this is the noble gas that is closest to it.

Next, recall that since the orbitals are higher in energy that the orbitals, electrons will be lost from the orbital first.

The normal electron configuration for is as follows:

has lost electrons. It will lose the first two electrons from the shell, then it will lose electron from the shell, giving it the following electron configuration:

Start by finding the noble gas core. For tungsten, this will be xenon as this is the noble gas that is closest to it.

The normal electron configuration for is as follows:

Recall that electrons are lost in the highest energy level subshell first.

has lost electrons. It will lose the first two electrons from the shell, then it will lose electron from the shell, giving it the following electron configuration:

Electrons of an atom are located within electronic orbitals around a nucleus. The electrons of each atoms have their own specific energy level called principal energy level. When electrons are excited by absorbing energy the electrons can jump to a high energy level. Then when an electron drops back to a lower energy level the electron emits the energy. Therefore, when an atom moves from a lower energy state to a higher energy state. the electrons absorb energy.

Each element has a unique electron configuration that represents the arrangement of electrons in orbital shells and sub shells. There are four different orbitals, s, p, d, and f that each contain two electrons. The p, d, and f orbitals contain subshells that allow them to hold more electrons. The orbitals for an element can be determined using the periodic table. The s-block consists of group 1 and 2 (the alkali metals) and helium. The p-block consists of groups 3-18. The d-block consists of groups 3-12 (transition metals), and the f-block contains the lanthanides and actinides series. Using this information we can determine the full electron configuration of sodium.

To do this, start at hydrogen located at the top left of the periodic table. Hydrogen and helium are in the first s orbital and account for . Next, we move to the second s-orbital that contains lithium (Li) and beryllium (Be), which accounts for . Then we move to boron, carbon, nitrogen, oxygen, fluorine, and neon, which are all in the p-block and account for . There is no 1p orbital. Finally, we are at sodium, which is in the s-block and accounts for . Therefore the full electron configuration of sodium is .

Each element has a unique electron configuration that represents the arrangement of electrons in orbital shells and subshells. There are four different orbitals, s, p, d, and f that each contain two electrons. The p, d, and f orbitals contain subshells that allow them to hold more electrons. The orbitals for an element can be determined using the periodic table. The s-block consists of group 1 and 2 (the alkali metals) and helium. The p-block consists of groups 3-18. The d-block consists of groups 3-12 (transition metals), and the f-block contains the lanthanides and actinides series. Using this information we can determine the electron configuration of iodine in nobel gas configuration.

The nobel gas configuration is a short hand to writing out the full electron configuration. To do this, start at the nobel gas that come before the element of interest. In the case of iodine, the nobel gas is krypton. Therefore, the electron configuration will begin with , and this will be the new starting place for the electron configuration.

After krypton comes the s-block, which contains elements with the atomic numbers 37 and 38 that account for . Then comes the d-block containing elements 39-48 that account for . Finally comes the p-block containing elements 49-53 that account for . Therefore, the electron configuration of iodine in nobel gas configuration is .

By definition, isotopes of a given element have the same number of protons and electrons, but differ in the number of neutrons. This causes a difference in the mass number (protons + neutrons) as well. Neither the number of protons nor the number of electrons changes with different isotopes of the same element.

In order to find the molar mass of an atom from its isotopes and their natural abundances, use the following equation:

for all the given isotopes.

Since chromium has four isotopes, we will write the following equation to find its atomic mass:

Isotopes are versions of an element with different numbers of neutrons. Hydrogen has three naturally occurring isotopes. , sometimes called protium, contains one electron, one proton, and no neutrons. , called deuterium, contains one electron, one proton, and one neutron. , called tritium, contains one electron, one proton, and two neutrons. Hydrogen has no such isotope that contains three neutrons.

Each element is defined by the number of protons its atoms contain. For example, hydrogen has one proton, helium has two protons, and lithium has three protons. Each element also has a characteristic number of neutrons. For example, hydrogen has zero neutrons, helium has two neutrons, and lithium has four neutrons.

Some elements, however, also have different "versions" of themselves: atoms which have a different number of neutrons, called isotopes. For example, there are three isotopes of hydrogen. has one proton and zero neutrons. has one proton and one neutron. Lastly, has one proton and two neutrons. Carbon is another such element that has different isotopes.

The noble gases possess a full octet of electrons. They have the largest first ionization energies because of their tendency to keep all of their valence electrons. Halogens have the highest electron affinity; therefore, they have high—but not the highest—ionization energies. The alkali and alkaline earth metals have low electron affinities and low ionization energies. Last, the metalloids possess ionization energies that are neither high nor low.

The metallic character of elements increases as you move down a group. All of the listed elements are in Group 5. Since is the furthest down, it must have the most metallic character.

When looking at a periodic table, you should notice that all of these elements are in the same period. Recall that atomic radii decrease as you move right on a period. Thus, this is the order of the elements by decreasing radius:

, or gallium, has the largest radius because it is the furthest left on the periodic table.

The correct answer is

has the most nonmetallic characteristics while has the most metallic characteristics. According to periodic trends, metallic character decreases from left to right across a period and increases top to bottom. Therefore, will show less metallic character than .

The atomic radii is the size of an atom when it is not bonded to any other atoms. The periodic table can be used to estimate the size of the atomic radii of atoms. As you move down the periodic table the atomic radii increase, but as you move from left to right on the periodic table, the size of the atomic radii decrease.

Sodium, aluminium, phosphorus, sulfur, and chlorine are all in the same row of the periodic table. Since the size of the atomic radii decreases as you move from left to right on the periodic table, the element furthest to the left will be the largest. Therefore, sodium is the largest atom out of the group.

The atomic radii is the size of an atom when it is not bonded to any other atoms. The periodic table can be used to estimate the size of the atomic radii of atoms. As you move down the periodic table the atomic radii increase, but as you move from left to right on the periodic table, the size of the atomic radii decrease.

Beryllium, magnesium, calcium, strontium, and barium are all in the same group on the periodic table, so the smallest element is the element closest to the top of the periodic table since the atoms become larger as you go down the periodic table. Therefore, the smallest atom of this group is beryllium.

Electronegativity refers to the ability of an atom to attract and bind electrons. If the valence electrons are less then half full, then it takes less energy to lose an electron than gain electron making these atoms less electronegative. If the valence electrons are more than half full, then it takes less energy to gain electrons compared to losing an electron; therefore these electrons are more electronegative. The periodic table can be used to predict the electronegativity of the atom and how it compares to other atoms. As you move left to right of the periodic table, the electronegativity increases because the atoms on the right side of the periodic table have more valence electrons, and smaller radii. As you move down the periodic table the electronegativity decreases because the atomic number increases resulting in a greater distance between valence electrons and the nucleus causing less pull on the valence electrons.

Using the electronegativity periodic trend, we can predict which of the atom's is most electronegative. Aluminium, silicon, phosphorous, sulfur, and chlorine are all in the same row in the periodic table. Therefore, chlorine is the most electronegative because it is the farthest right on the periodic table so it has the most valence electrons and it will cost less energy to gain an electron than lose an electron.

Electronegativity refers to the ability of an atom to attract and bind electrons. If the valence electrons are less then half full, then it takes less energy to lose an electron than gain electron making these atoms less electronegative. If the valence electrons are more than half full, then it takes less energy to gain electrons compared to losing an electron; therefore these electrons are more electronegative. The periodic table can be used to predict the electronegativity of the atom and how it compares to other atoms. As you move left to right of the periodic table, the electronegativity increases because the atoms on the right side of the periodic table have more valence electrons. As you move down the periodic table the electronegativity decreases because the atomic number increases resulting in a greater distance between valence electrons and the nucleus causing less pull on the valence electrons.

Using the electronegativity periodic trend, we can predict which of the atom's is least electronegative. Oxygen, sulfur, selenium, tellurium, and polonium are all in the same group of the periodic table. Therefore, polonium is the least electronegative because it is closest to the bottom of the periodic table and has the largest atomic numbers. Since polonium has the largest atomic number, there is a greater distance between the valence electrons and the nucleus resulting in a decreased pull on the valence electrons. Therefore, it is easier to lose a valence electron compared to atom's with a smaller atomic number.

The absorption of energy excites electrons to higher energy levels, from a lower to a higher one. Since electron shells grow increasingly closer in energy and increases, the highest gaps occur between lower level shells. Thus, in this question, the largest gap between any two principle quantum number occurs between the first energy level and the third energy level.