Ch 2-The Chemical Context of Life Flashcards
Why Chemistry Important
- chemicals make up our bodies and those of other organisms
Matter
- Matter
- anything that takes up space & has mass
- composed of elements
Element
- 92 natural, 26 man-made
- Names are abbreviated by 1 or 2 letters
- Ex: C, O, H, Fe, Al, etc.
- Substances that cannot be broken down to other substances by chemical reactions
Compounds
- Substance consisting of two or more elements in a fixed ratio
- different characteristics than elements
Atoms
- The smallest particle of matter that still retains the properties of an element
- Consist of subatomic particles
Molecules
- a group of atoms bonded together
- the smallest fundamental unit of a chemical compound
Atomic number & Mass number
- Atomic number
- number of protons in an atom
- Written as a subscript to the left of chemical symbol
- Mass number
- sum of the number of protons & neutrons
- written as a superscript to the left of the chemical symbol
Interrelationship between protons, neutrons, & electrons
Protons and neutrons are basically found at the atomic (atom) nucleus while elecctrons form the shell of the atom, moving around the nucleus.
Electrons how to be donated or shared between atoms
Electrons can be transferred, shared, or cause charge disparities between atoms to create bonds, including ionic, covalent, and hydrogen bonds, as well as van der waals interactions.
Compare & Contrast ionic, covalent, hydrogen bonds, van der waals interaction
Covalent bonds are the strongest, then ionic, hydrogen, Van der Waals
Valence Cell
Are the outermost shells
Innermost cell is full with how many electrons?
2 electrons
2nd & 3rd cells can hold up to how many electrons?
8 electrons
Chemically stable & reactive atom?
The stability of atoms depends on whether or not their outer-most shell is filled withe electrons.
How atomic structure affects chemical bonding?
Interactions (or attractions) that hold atom close together.
