test Thursday Feb 16th 2017 unit 1

test Thursday Feb 16th 2017 unit 1

1. measuring & scientific notation

   • significant: non-zero, zeros between significant digts
   • not significant: zeroes before a number,

2. atomic structure

   • electron shells: 2,8,8,18,18

3. periodic trends

   • more electrons= denser=lower radius
   • more electrons= greater need to complete shell= higher electronegativy & energy needed to take away electrons

4. trends in bonding

   • elctronegativity difference dictates how polar it is, share/take
   • metals give away electrons, two non metals share, two metals don't react
   • all elements want to have a complete outer shell