Progress: 24/27 Ionic Bonding Tutorial
Rotate the crystal, then count the number of ions in
the crystal, and select the correct ionic formula:
What is the formula for this
ionic crystal?
CaF
CaF2
CaF
Calcium lons:
-28
Ca, F8
+ +
Fluoride lons:
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Which statements explains what the fossil records indicates? check all that apply. a) earth is 4.5 billion years old b) many organisms have become extinct c) mammals have always existed on earth d) mass extinctions have occurred several times on earth e) the amount of water on earth has decreased over time?