Blood cells are produced in the bone marrow and the bone marrow is part of the skeletal system. So the answer would be skeletal system<em>. </em>
Answer:
The subphylum Chelicerata (New Latin, from French chélicère, from Greek χηλή, khēlē "claw, chela" and κέρας, kéras "horn")[1] constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, arachnids (including scorpions, spiders, and potentially horseshoe crabs[2]), and several extinct lineages, such as the eurypterids.
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.
