Answer:
D
Explanation:
The simple answer is the electrons in the outermost energy level.
Hydrogen has 1 electron in the outermost energy level.
Magnesium has 2 so this tells you that magnesium has a charge of 2
Oxygen has 6 oxygen has a charge of - 2
Fluorine has 7
For most elements, the electrons in the most outer ring determine the valence of the element.
Notice that the non metals work differently than the metals. Mg may have a charge of 2 and that is the number of electrons in the valence right.
Oxygen is a non metal it has a charge of - 2. It gets 6 electrons by subtracting the number of its charge from 8.
Answer: The ocean dissolves carbon dioxide from the atmosphere, and it is used by phytoplankton during photosynthesis.
It is a very interesting question - the technology is real and the research on eDNA published in a journal in 2017.
eDNA stands for enviornmental DMA sampling. It allows scientist to test water samples for the presence of the DNA of the invasive fish species. It is more effective than traditional methods of sampling because it does not require trapping or sighting of the invasive species. Water samples can be collected anywhere any time and the DNA results are as accurate and detailed as collected from the invasive species themselves. It provides a complete picture of what invasive species are there.
These unsegmented worms have a full digestive system even when parasitic.
