SES194 Energy in Everyday Life
SES194 Energy in Everyday Life SES194
Popular in Energy in Everyday Life
Popular in Business
This 7 page Bundle was uploaded by Sarah Booth on Thursday October 13, 2016. The Bundle belongs to SES194 at Arizona State University taught by Frank Timmes in Fall 2016. Since its upload, it has received 5 views. For similar materials see Energy in Everyday Life in Business at Arizona State University.
Reviews for SES194 Energy in Everyday Life
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/13/16
SES194 Energy in Everyday Life Unit 2 Valence Electrons The chemical properties of atoms are determined by the conﬁguration of the outermost electrons in an atom. -If the outer electron conﬁguration of two atoms are still the same, they will combine with still other atoms in about the same way (to make roughly similar chemical compositions). Example Oxygen and Sulfur each have 6 outer valence electrons and when you form chemical compounds with them you’re gonna have similar physical characteristics (boiling points) and take similar amounts of energy to remove an outer electron from atoms with similar outer shell conﬁgurations. -Atoms appearing in the columns of the periodic table of the elements exhibit similar chemical behaviors. -The 1-8 at the top of each column represents the number of valence electrons that element has.As shown below. -Atoms possessing certain conﬁgurations are resistant to indulging in chemical reactions. -The electrons in these atoms are not easily removed nor can an extra electron be added easily. -Such atoms are gasses at room temperature and are inert (or noble) gases. -These atoms have a full outer shell of electrons, and make up the last column of the periodic table (smallest of any). -If an atom has one outermost electron, it is relatively easy to strip that electron and make the atom positively charged.These atoms are in the ﬁrst column of the periodic table. -If an atom is lacking one electron for a full outer shell, it is easy to get it to accept an extra electron and become a negatively charged atom.The atoms are in column seven of the periodic table. -Many chemical compositions occur because atoms of the ﬁrst type (such as sodium) gives up one of its electrons to an atom of the second type (such as chlorine). Since the ionized atoms have opposite charges, they attract one another to form compounds (such as NaCl - table salt). SES194 Energy in Everyday Life Unit 2 BondTypes -In an ionic bond, atoms are bound together by the attraction between oppositely charged ions. -In a covalent bond, the atoms are bound by shared electrons. -Such sharing of electrons allows each atom to attain the equivalent of a full outer shell, a stable conﬁguration. -Pure ionic bonding in which one atom “steals” an electron from another atom cannot exist.All real ionic compounds have some degree of covalent bonding, or electron sharing.This “ionic bonding” is giving when the ionic character is greater than the covalent character. -Some atoms in the periodic table have two “extra” electrons (column 2) or three “extra” electrons of a full shell (column 6) or lack three electrons of a full shell (column 5). -The atoms of column 4 can be thought of as either processing four extra electrons or lacking four electrons. -Because of the many ways carbon can combine with other elements, molecules with carbon can exist in numerous forms. -Organic chemistry is a branch of chemistry that deals only with carbon compounds.The name recognizes the importance of carbon for life as we know it. SES194 Energy in Everyday Life Unit 2 Bond Energetics Compounds form from atoms when the atoms can ﬁnd a lower energy state than when the atoms are alone. -The atoms reach a lower energy state by giving up some of their energy to make a bond. -Chemical reactions which give off energy as they proceed are called exothermic. Chemical reactions involving burning (oxidation reaction) are exothermic. Example Consider billiard balls on a pool table. It is easy for the balls to roll into holes and fall below the surface, where they can mix with the other balls.To unix the balls, we have to give them back to the gravitational energy they gave up in falling down the hole, by doing work as we lift them back onto the table. -The atoms may be separated, and bonds broken, only if energy is added to the system. Chemical reactions which absorb energy as they proceed are called endothermic.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'