Answer: The answer is they are not closely packed
Explanation: HOPE THIS HELPS!!
I don’t know what the “cheater” way is, however you can easily judge how many valence electrons an element has by looking at its group number on the periodic table.
Bonding in chemistry is completely and totally due to electrons. Every element wants 8 electrons in its outer shell in order to be stable. This is what we call the “Octet Rule”.
The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
Thus, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Blank 1: nothing (to keep 2 total nitrogen)
blank 2: 3 (to make 6 total hydrogen)
blank 3: 2 (to make 2 total nitrogen and 6 total hydrogen)
hope this helps!! :)
Answer is none of the above