AP Biology Unit 1, AP Biology Unit 2
Study online at https://quizlet.com/_fij4p3
1. Matter Anything that takes up space and has mass.
2. Element Substance that cannot be broken down to other sub-
stances through chemical reactions. Each has a symbol.
92 occurring in nature.
3. Compound Substance consisting of two or more different elements
combined in a fixed ratio.
*Characteristics different than those of its elements
4. CHON 4 elements essential to life
5. Trace Elements Required by an organism only in minute quantities.
6. Atom Smallest unit of matter that retains the properties of an
element. Composed of subatomic particles. Mostly empty
space.
7. Subatomic parti- Neutrons, protons, electrons. Make up atoms.
cles
8. Proton One unit of positive charge. Approximately one dalton.
Located in nucleus.
9. Electron One unit of negative charge. Located outside of nucleus.
, AP Biology Unit 1, AP Biology Unit 2
Study online at https://quizlet.com/_fij4p3
10. Atomic Nucleus Dense core packed with protons and neutrons.
11. Neutrons Electrically neutral. Approximately one dalton.
12. Atomic Number The number of protons (which is unique to that element)
and written as a subscript to left of element symbol. Also
tells us number of electrons since P=E if atom is neutral
13. Mass Number Sum of the protons and the neutrons. An approximation
of the atomic mass.
14. Isotopes Same number of protons, but different number of neu-
trons and therefore different mass. Same element.
, AP Biology Unit 1, AP Biology Unit 2
Study online at https://quizlet.com/_fij4p3
15. Radioactive Iso- One in which the nucleus decays spontaneously, giving
tope off particles and energy. Can decay to a different element.
Have useful applications.
16. Energy Capacity to cause change
17. Potential Energy Energy matter possesses because of its location or struc-
ture. Electrons have this based on distance from nucleus.
18. Electron Shells Where electrons are found, each with characteristic av-
erage distance and energy level. Electrons can change
these by absorbing or losing energy.
19. Valence Elec- Electrons in the outermost shell.
trons
, AP Biology Unit 1, AP Biology Unit 2
Study online at https://quizlet.com/_fij4p3
20. Chemical Bonds The attraction that holds atoms together during an inter-
action.
21. Covalent Bond Sharing of a pair of valence electrons by two atoms.
22. Molecule Two or more atoms held together by covalent bonds.
23. Single Bond One pair of shared electrons.
24. Structural For- H--H. Notation which represents both atoms and bonding.
mula
25. Double Bond Sharing two pairs of valence electrons.
26. Valence Bonding capacity. Equal to the number of unpaired elec-
trons required to complete the outermost (valence) shell.
27. Electronegativity The attraction of a particular kind of atom for the electrons
of a covalent bond.
28. Nonpolar Cova- Covalent bond in which electrons are shared equally.
lent Bond
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller TUTORliz. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
