Ch 2-The Chemical Context of Life Flashcards Preview

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Flashcards in Ch 2-The Chemical Context of Life Deck (18)
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1

Why Chemistry Important

  • chemicals make up our bodies and those of otherr organisms
  • physical environment-water, air
  • chemical reactions

2

Matter & Elements

  • Matter
    • anything that takes up space & has mass
    • composed of elements
  • Elements
    • Substances that cannot be broken down to other substances by cemical reactions
    • 92 natural, 26 man-made
    • abbreviated by 1 or 2 letters

3

Element 

  • 92 natural, 26 man-made
  • Names are abbreviated by 1 or 2 letters
  • Ex: C, O, H, Fe, Al, etc.

4

Compounds

  • Substance consisting of two or more elements in a fixed ratio
  • different characteristics than elements

5

Atoms

  • The smallest particle of matter that still retains the properties of an element
  • Consist of subatomic particles

6

Molecules

  • a group of atoms bonded together
  • the smallest fundamental unit of a chemical compound

7

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

8

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.

9

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.

10

Compare & Contrast ionic, covalent, hydrogen bonds, van der waals interaction

Covalent bonds are the strongest, then ionic, hydrogen, Van der Waals

11

Valence Cell

Are the outermost shells

12

Innermost cell is full with how many electrons?

 2 electrons

13

2nd & 3rd cells can hold up to how many electrons?

8 electrons

14

Chemically stale & reactive atom?

The stability of atoms depends on whether or not their outer-most shell is filled withe electrons.

15

How atomic structure affects chemical bonding?

 Interactions (or attractions) that hold atom close together.

16

Electronegativity

Attraction for shared electrons

(more electronegative atoms pull harder)

17

Polar and Nonpolar covalent bond

  • Nonpolar 
    • atoms share the electron equally
  • Polar
    • one atom is more electonegative
    • atoms do not share the electron equally

18

Biological significance of isotopes

  • Nucleus decay spontaneously, giving off particles and energy
  • radioactive tracers-diagnostic tools in medicine
    • used in imaging instruments