Exam 1 - Lecture 2 - Life, Chemistry, & Energy Flashcards
(23 cards)
What are the 6 most abundant elements in life?
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous, & Sulfur
How are elements defined?
Elements are defined by the number of protons
What is the atomic number?
The number of protons in an element?
What is an isotope?
A variation of an element that has a different number of neutrons than the “standard” amount for that specific element
How do you find the atomic mass of an element?
of protons + # of neutrons
What is the Bohr model?
States that most of the space between the nucleus and electron orbitals is empty space
How many electrons can each orbital hold?
2 electrons
What comprises an electron shell?
Orbitals of similar energy
How does distance from the nucleus impact an electron’s energy??
Electrons have more energy the farther away they are from the nucleus
What is the valence shell?
The shell where the outermost/highest energy electrons (valence electrons) are located
What does the valence shell determine?
The chemical properties of an element
How can you predict the number of electrons in an element’s valence shell?
By using their atomic number to find their total number of electrons and filling each orbital in order
(note: first orbital only accepts 2 electrons, rest of orbitals can take 8 electrons )
Why do elements want to have a “full” valence shell?
Because that is when they are at their most “stable” state
What are some of the various ways elements can reconfigure the number of electrons in their valence shell?
(3 ways)
By forming covalent bonds (sharing electrons)
By forming ionic bonds (losing or gaining electrons)
By redox reactions ( transferring electrons and their energy)
When two or more atoms react to acquire a full valence shell, it forms a _______
Compound
How many electrons does each orbital require to be considered “filled”
2 electrons per orbital
Based on the number of electrons necessary to fill an orbital, how many orbitals are in each shell? How many possible electrons can fill each shell?
The first shell only has 1 orbital, ∴ has room for 2 electrons
The second shell and on have 4 orbitals, ∴ has room for 8 electrons
What is an ion?
An atom that is not electrically neutral (can have a positive or negative charge)
What is a cation?
A positively charged ion
What is an anion?
A negatively charged ion
In the context of an aqueous environment, which is stronger - an ionic bond or covalent bond?
Covalent bond
What property/properties is/are responsible for surface tension?
Cohesive properties
What property/properties is/are responsible for capillary action?
Adhesive AND cohesive properties
