Answer:
vertebral column
Explanation:
A lamprey's body has smooth, scale-less skin and two dorsal fins, but has no lateral line, no vertebrae, no swim bladder, and no paired fins.
Tuna is vertebrate.
The Lewis structure of P₄ is shown in 3-D form. The two bottom corner P atoms are facing right in front of us, one P atom behind the two, and one P above it. Each line represents 2 electrons. When you add the lone electrons, you get a total of 20 valence electrons.
Formal charge of each P: 5 - (2 +1/2*6) = 0
Temperature decreases (?)