Answer:
When the Zebra arrived they ate all the food so the Unionid mussels declined as they died from the lack of food. Causing the Zebra Zebra numbers to increase and Unionid numbers to decline.
Answer: the longitude line rotates with Earth, 360 degrees in 24 hours.
Explanation: In the old days, the position of the sun was used to tell which time of the day it is. But more modern findings, has shown that the longitude line matters too.
Answer:
C.
Explanation:
The electronic configuration of N (7 electrons): 1s² 2s² 2p³.
The orbital 1s is filled with two electrons and their spinning direction is opposite and also electrons of 2s.
3p contains (3 electrons) should fill the 3 orbitals firstly. Every orbital contains 1 electron and be in the same spin direction.
So, the right choice is c.
A is wrong because 2 electrons of 3p are paired in the first orbital before filling every orbital.
B is wrong because the 2 electrons of 1s and 2s are in the same direction and also 2 electrons of 3p are paired in the first orbital before filling every orbital.
D is also wrong the 2 electrons of 1s and 2s are in the same direction and the electron in the second orbital of 3p are in opposite direction of the other 2 electrons.
A single ringed nitrogeo base is thymine (C)