This morning, I awoke a little earlier than usual. As I lay there for a minute, half asleep and half awake, I became conscious of a song refrain going around in my head. It was the refrain of “Alleluias” heard from our previous Sunday Mass. However, this was four days later, at 5:00 in the morning. I had at least another hour and a half before I needed to get up, and this “Alleluia” chorus kept going around in my head. “Is this the beginning of the blog I prayed for last night?” Happily, it turned out that it was!
“Alleluia” is an expression of rejoicing, meaning “God be praised!” As we continue to rejoice in the Risen Christ this Easter, the Dominican Sisters of Peace also thank and praise God as we celebrate our Tenth Anniversary! Ten years ago on April 12, 2009, seven Dominican congregations united for the sake of the mission, forming a new congregation, the Dominican Sisters of Peace. For several days in July 2019, during our annual Assembly, the congregation will celebrate together the new life created from this union. God be praised for “doing something new” in our lives of faith and commitment.
God be praised—for the lives of the six new women who felt called to join the Dominican Sisters of Peace as Candidates during the first ten years of our existence! One of these women, Sister Bea Tiboldi, OP, recently professed her Perpetual Vows in April 2019, the month of our tenth anniversary. Sister Elizabeth Jackson, OP, professed Perpetual Vows in December 2018. Two others, Sister Ana Gonzalez, OP and Sister Margaret Uche, OP, professed Temporary Vows in July2018. Sister Phuong Vu is completing her Canonical year as novice in the Collaborative Dominican Novitiate and Candidate Ellen Coates is preparing to begin her novitiate year at the Collaborative Dominican Novitiate in August 2019. The blessings continue, as the Congregation prepares to receive a new Candidate, Annie Killian, in July 2019.
God be praised—for the five women who were in temporary vows in several of the former congregations that united and were among the first to profess their Perpetual Vows in the Dominican Sisters of Peace! They are Sisters Hoa Nguyen, OP, Mai-Dung Nguyen, OP, Patricia Connick, OP, Mary Vuong, OP, and yours truly, Patricia Dual, OP.
God be praised—for several women who are in serious discernment with the Dominican Sisters of Peace and the group of 14 plus women who are currently discerning a call to religious life with our vocation ministers!
Alleluia! Alleluia! Alleluia! The Dominican Sisters of Peace have much to praise God for as we celebrate this Tenth Anniversary! All of the Sisters mentioned represent new life, a continuing of the Dominican heritage passed on by all of our current Sisters and all those who have gone before. How appropriate to offer our praise and gratitude during the joy of this Easter season.
I invite you to join us in giving thanks by praying with us part of our Tenth Anniversary Prayer:
“Faithful God, We give you thanks for This grace-filled decade as Dominican Sisters of Peace And Associates… Carry us Faithful God, into our future Strengthen and lengthen our roots Into a new growth of understanding.”
(The Anniversary Prayer)
Wondering if you might be called to religious life? Call us, we can help!
Chemistry describes the connections (a.k.a. bonds) among atoms. At this level, it is the sharing or exchange of only the outermost electrons which facilitates an increase in complexity from smaller atoms to molecules, crystals or metals. In this sharing or exchange of electrons, properties are completely changed. As we will soon see, community at every level is transformative!
BONDING BY SHARING BETWEEN ADJACENT ATOMS (COVALENT BONDING)
To begin, we start with two hydrogen atoms in isolation from one another. Their energy in this state is defined as zero as shown above on the right side of the picture. As the two atoms approach one another they are attracted to one another and so their combined energy is gradually reduced to a lower value until the lowest energy is achieved at the bottom of the curve.
This distance where the two atoms have the most stable energy is called the bonding distance or bond length and signals the formation of the resulting molecule. If the two atoms continue past this point to come closer together, they repel one another increasing the molecule’s overall energy once again. In response to this repulsion, the atoms return to the “sweet spot” where the energy is the lowest.
A single bond distance defines the hydrogen molecule and a specific lowering or release of energy is associated with the formation of that bond, the bondingenergy, for two hydrogen atoms. To break the bond and again separate the atoms requires an input equal to that energy. Hence, the molecule is more “stable” than two atoms existing separately. Coming together is about sacrifice yes, but also synergistic benefit.
A molecule is not the mere juxtaposition of more than one atom with others. It is about a new entity where the outer electrons are shared by the two nuclei making up the molecule. This sharing of electrons is so important, chemists use different terms to name the locations of the electrons. Before the two hydrogen atoms begin sharing the electrons, we say they exist in “atomic” orbitals, emphasizing their isolation from one another.
After the association of the two hydrogen atoms we say they now exist in “molecular” orbitals emphasizing instead their new identity as a hydrogen molecule instead of two hydrogen atoms. It is in this sharing of electrons that the two atoms are transformed into a single molecule. We call the sharing of the electrons, “covalent”, a co-operative sharing of the outer shell, or valenceelectrons from each of the atoms.
The combination of two atoms to form a hydrogen molecule is transformative for the atoms. The new hydrogen molecules have different physical and chemical properties than the originally separate hydrogen atoms. New possibilities for reactions now exist for the molecule that were not available before and other possibilities have been given up. The molecule is a trade-off with greater complexity.
Covalent bonds not only exist between atoms of the same type, but also between atoms of different types. These almost always share their bonding electrons somewhat unevenly, because the original atoms each have a different attraction for the electrons. Examples include water, H-O-H, better known as H2O, and carbon dioxide, CO2, or O=C=O. In both these bonds, the oxygen atom is known to attract the electrons more strongly than either the hydrogen or carbon atoms, resulting in uneven or polar bonds.
What is perhaps more amazing is that because water is a bent molecule it will interact with electric and magnetic fields, but carbon dioxide will not because it is linear. The details are not important here, except to say even the three-dimensional shape produced by the coming together of atoms makes the difference in the properties of the molecule.
Sharing of these outer shell electrons between atoms and the formation of a
3-dimensional molecule from atoms leads to an abundance of possibilities not open to just atoms alone. In fact, in the world of practical chemistry, it is the rearrangement of these very bonds that leads to the transformation of one compound to another, what we call chemical reactions.
Covalent compounds exist as molecules, literally “little lumps” of matter, very small communities where electrons are shared as needed among the member atoms. The elements called nonmetals such as oxygen (O), hydrogen (H), and carbon (C) (see above), participate in this type of sharing. They are known to hold onto these outer electrons quite tightly (have high ionization energies) and so although they are not likely to give them away, sharing is possible.
Metal atoms by contrast hold onto their electrons more loosely than nonmetals (have low ionization energies), so we will see a completely different type of bonding as atoms of metals and non-metals combine as discussed in the second section and as atoms of metals come together themselves (the third section)
In the periodic table notice the existence of “metalloids” which are intermediate in their properties between metals and nonmetals. These elements sometimes behave like metals and at other times like nonmetals, depending on what other elements are around them. (Sounds like some people whose behavior is dependent on their environment, eh?)
BONDING BY COMPLETE EXCHANGE (IONIC BONDING)
Another possibility for the combination of atoms involves the transfer of electrons rather than their equal or unequal sharing. A beautiful example of this is common table salt: NaCl, sodium chloride. Sodium (Na) is a highly reactive metal; indeed, it will violently react with water and form a solution of lye [drain cleaner], NaOH, in the process. Chlorine (Cl2), a yellow-green gas is poisonous, and was used in World War I as a chemical weapon before its ban by the Geneva Convention.
Yet, when sodium and chlorine are existent together as sodium chloride (NaCl), we obtain again an entirely new set of properties. Some of its most common uses include, but are not limited to: flavoring our food, melting snow and ice on our roads and sidewalks, softening our well water, and making paper and rubber.
How is it that this transfer of electrons comes about? Sodium metal, Na, begins with 11 electrons, in what we call “shells” of 2, 8, and 1. Each non-metal chlorine atom, Cl, begins with 17 electrons, with 2, 8, and 7 electrons in its shells. Shells listed first are nearest the nucleus and not likely to be exchanged, but those listed last, the valence, or outer-shell electrons, are furthest from the nucleus and are more loosely held.
As shown in the diagram, by the simple transfer of the one valence electron in the last shell from sodium to the last shell of 7 electrons in chlorine we are left with the sodium ion, Na+, with 10 electrons in shells of 2 and 8 and the chloride ion, Cl–, with 18 electrons in shells of 2, 8, and 8.
For reasons we won’t explore here these octets, or sets of 8 electrons, in the last shell are much more stable than the electron arrangement in the neutral atoms, not containing these octets in the last shells. The resulting Na+ and Cl– ions, being opposite in charge, are strongly attracted to one another.
In fact, we call sodium chloride, NaCl, for simplicity’s sake. This one-to-one ratio is simply the lowest ratio (1:1) of atoms in sodium chloride. The actual number of pairs is overwhelmingly great at room temperature. Atoms come together in such great numbers that we can see a single crystal of sodium chloride at room temperature. Think of that the next time you hold a crystal of salt in your hand!
Ionic compounds are almost always composed of a metallic element with a nonmetallic clement. The loosely held electrons are donated from the metal to the nonmetals, which hold on tightly to them. Examples include
calcium chloride, CaCl2 (used to melt snow from our sidewalks in winter)
sodium nitrate, NaNO3 (used to preserve some lunch meats and bacon), and
aluminum sulfate, Al2(SO4)3 (used in the purification of drinking water).
So, what difference does a transfer of electrons cause compared to sharing? Check out the contrasting properties of covalent and ionic compounds:
ions in crystals
types of elements
nonmetals with nonmetals
metals with nonmetals
physical state (250C)
usually gases, also liquid & solid
solubility in water
usually lower, except for acids
electrical conducitivity of solid
does not conduct electricity
does not conduct electricity
electrical conductivity of solution with water
does not conduct electricity, except for acids
does conduct electricity
BONDING BY OPEN AND WIDESPREAD SHARING (METALLIC BONDING)
Metals have a third way of coming together. Individual atoms of metals have loosely held electrons in their outermost shells as we know from their easy donation of electrons to nonmetals in ionic bonding. Yet when metals come together with other metals the sharing is remarkably different: they now share the electrons over a vast community. The outermost electrons are free to move in a matrix of nuclei with only their inner shells of electrons. We call these freely wandering valence electrons, the “sea” of electrons.
This property is what makes metals such wonderful conductors of electricity. The electrons are free to move throughout the metal from one place to another, when moved by an electric field. This sea of electrons is also the reason that metals are malleable and can be pounded in sheets, like aluminum or gold foil. Metals are also ductile and can be drawn in wires for the same reason. We use copper, for instance, to wire our homes and businesses.
widespread connection among metal atoms
types of elements
metal with metal
usually very high
physical state (250C)
solid, except for mercury (Hg)
solubility in water
does not dissolve in water
electrical conductivity of solid
conducts electricity easily
electrical conductivity of solution with water
no electrical conductivity due to dissolution
The way electrons are either shared or exchanged among atoms and how that leads to the creation of molecules, metals, or crystals, can remind us of the benefit for us as human beings to freely exchange or share our resources. For us too, the possibility of greater complexity and new possibilities awaits.
I don’t know about you, but I’m good at donating that to which I’m not particularly attached to someone in need. And, I have become better at receiving what seems to be “extra” from other people, especially if I really need it. I do the transfer of resources to and from myself (an ionic process) fairly well.
And, I suppose I’m even OK at sharing what little I have with others if they put in a similar share and none of us is particularly attached to what we’re sharing. My instinct to follow the wisdom of the metallic atoms seems intact too.
But, when I look at what I’m attached to, especially when I think a resource is scarce, I have grown accustomed to keeping “extra” for myself. My first inclination is the opposite of sharing, hoarding. So it makes me wonder: what new possibilities I’ve been missing because I haven’t participated in as much sharing (a covalent process) as the atoms do naturally? It’s a good question!
There’s a lot to learn from atoms, besides academic chemistry!
Bless the Lord, all you molecules that share electrons,
All you atoms that transfer electrons, bless the Lord.
All you metals with your seas of electrons, bless the Lord,