Essay on Biology Notes

Submitted By owow97
Words: 496
Pages: 2

Science Chapter 1
Basic Chemistry:
*Mass a anything that has mass and takes up space -All matter is composed of elements
-substance that cannot be broken down into simpler substances Ex: oxygen, hydrogen, and carbon -each element has a set of properties that distinguish it from others
*Atom is the smallest particles of an element, basic building block of life
*Atom Structure: -Nucleus: Protons= postive charge Neutrons=no charge -Surrounds nucleus: Electrons=negative charge Structure of an atom:
*Same element, different number of neutrons -Carbon-12, C-13, C-14
*Isotopes can be unstable, like Carbon 14, and when these are broken apart, radiation is given off
Use of Radioactive Isotopes:
*Cancer treatment
*Smoking detectors (Americium- 241)
*Bone imaging, CT scans
*Carbon-14 dating
*Atoms of 2 or more different elements together
*Example: Table Salt (NaCl) and water (H2O)
*Only form when it’s more stable to be together than to be apart
Covalent Bonding:
*Covalent bonding atoms bond by sharing electrons
*Goal: Fill energy levels
*Groups of atoms held together by covalent bonds
Ionic Bond:
*Ions: Charged particle made up of atoms
*A positively charged particle bonding together
*Ex: NaCl
*Less common than covalent molecules
*Substances mixed together, but THEY STAY SEPARATE
*Ex: Sand and Sugar & Oil and Water
*Mixture where substances are evelny spread
*Solute the thing being dissolved (Ex. Salt)
*Examples: Salt and Water & Sugar and Water
Ph Measurement of Acidity and Basicity of a Solution:
*Ranges from 0-14
*Acidic pH less than 7 -A lot Hydrogen ions (H+) released in water -Example: add HCl to water, the H+ are released (and Cl-)
*Basic pH higher than 7 -A lot of hydroxide ions OH- released (and Na+)
*Neutral pH is 7
Basic Chemistry:
-pH scale is based on powers of 10. Cola with pH 3 is 10 times more acidic than tomatoe juice with pH 4 -Living cells are very sensitive to pH of their environment. Our cells are in a pH of 7.2. If pH changes by 2/10th of a point, cells die

*Biochemistry is the study of the chemical interactions of living things.
*Biochemists study the structures adn physical properties of biological molecules. -Often are involved in the manufacture